Tony Fabris' BFG FAQ 1.3

Tony Fabris hat diese umfangreichen Informationen über BFG-9000, zusammengetragen.


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              _/_/_/_/    _/             _/_/_/_/_/           FAQ

================ The BFG FAQ, Version 1.3, December 28, 1995 ================

                Frequently Asked Questions About the BFG9000

                               By Tony Fabris

                    Contributors, in alphabetical order:

                Doug Bora ....... Content, Editing, Proofing
                Tod Bouris ............ Content, Playtesting
                Chris McAllen ......... Content, Playtesting
                American McGee .............. Technical Data
                Dean Stretton ..................... Proofing

================================= Disclaimer ================================

  This text is intended to give the public information about some elements
  of the computer game Doom and its sequels, by id Software. This text was
  not written by id Software, so bugging them about its contents is
  probably a very bad idea.

  Additionally, the computer game referenced in the text is of an adult
  and graphic nature. In no way is this text intended to promote violence
  of any kind. Any references to violence in this text are meant in
  relation to the playing of the computer game, not real violence. The
  author is adamantly non-violent.

  Additionally, this text is being presented in the form of a text-only
  computer file. Any illegal or damaging activity related to the use or
  transfer of this or any other computer file is not the responsibility of
  the authors.

=========================== Trademark Information ===========================

  All specific names included herein are trademarks and are so
  acknowledged: id Software, DOOM, DOOM II, THE ULTIMATE DOOM, QUAKE. Any
  trademarks not mentioned here are still hypothetically acknowledged.

============================= Copyright Notice ==============================

   This article is Copyright (c) 1995 by Tony Fabris. All rights reserved.

  You may make and distribute copies of this work in original form, so long
  as the copies are exact and complete, the copies include the copyright
  notice in its entirety, and the copies are in electronic form. You may
  not charge any sort of a price or fee relating to any copies of this work
  in any form.

=========================== Table of Contents ===============================

  Section 0 - Introduction
    0A. What is this FAQ about?
    0B. How was the information is this FAQ obtained?
    0C. How accurate is this information?
    0D. Where is the latest version of this and other FAQs?

  Section 1 - BFG Basics
    1A. What is the BFG9000?
    1B. What does 'BFG' mean?
    1C. Where can I find the BFG in the game?
    1D. What is the cheat code for the BFG?
    1E. Why is the BFG missing in my version?
    1F. What's this I hear about the original BFG?

  Section 2 - The Direct Hit
    2A. What is a direct hit?
    2B. How much damage does a direct hit do?
    2C. What are the limitations of a direct hit?

  Section 3 - The Blast Area
    3A. What is the blast area?
    3B. How much damage does the blast area do?
    3C. How long does the blast effect last?
    3D. How exactly does the blast area work?
    3E. What are the limitations of the blast area?
    3F. How many targets can it hit?
    3G. How does altitude affect it?
    3H. If I am only partially exposed, do I only take partial damage?
    3I. What happens if the attacker is fragged before detonation?
    3J. What about multiple BFG shots?

  Section 4 - Deathmatch Techniques
    4A. What is considered unfair when using the BFG?
    4B. What is the best way to defend against the BFG in a deathmatch?
    4C. What is the best way to attack with the BFG in a deathmatch?
    4D. What is the Silent BFG trick?
    4E. What is the Level One Strafe trick?

  Section 5 - Submitting Corrections
    5A. Common misconceptions
    5B. I think the FAQ is in error. How do I get it corrected?


-- Section 0 - Introduction -------------------------------------------------

0A. What is this FAQ about?

  A FAQ file, stated simply, is a Frequently Asked Questions file.

  This FAQ file describes, in as much detail as possible, the behavior of
  the BFG9000 weapon in the MS-DOS version of the games Doom, Doom II, and
  The Ultimate Doom. It is not intended to answer general questions about
  the game itself. Please refer to the other FAQ files for help in other
  areas of the game. You can also frequent the*
  newsgroups for more information.

  We began writing this FAQ out of necessity. We were frustrated at the
  apparent inconsistencies in the way the weapon seemed to behave during
  game play, especially during deathmatches. There were times when we
  would get killed by the weapon when we thought we were completely safe.
  Conversely, there were times when we thought we had used the weapon
  correctly against an opponent, but they walked away unscathed.

  Our intent is to provide players with enough information to attack
  effectively with the BFG, and to correctly defend against it in a
  deathmatch. Our hope is that this information will give players a new
  attitude toward the weapon. We want to transform it from "The weapon we
  love to hate" into "The thinking man's weapon".

0B. How was the information in this FAQ obtained?

  The primary source of information was American McGee at id Software. He
  patiently answered our questions while this FAQ was in its draft stages.
  He corrected several serious errors in our descriptions of the way the
  weapon calculates damage. He provided us with a great deal of detailed
  information, and reviewed the file during its development. His help was
  invaluable in putting this FAQ together.

  Most of the other information here is a result of careful testing during
  game play. Testing was performed on Pentium computers running the MS-DOS
  versions of Doom II and The Ultimate Doom. Tests were done both in single
  player mode and in 4-player deathmatch mode. Testing was performed on the
  regular levels as well as custom made levels. In some cases, a special
  .WAD file was created to test situations that would be difficult to
  reproduce with the regular levels.

0C. How accurate is this information?

  Fairly accurate. Accurate enough to base your playing strategies on.
  However, it has not been tested with every single version of Doom, and
  there may be differences among platforms. In addition, at the time of
  this writing, we were unable to verify every single item with American
  McGee. Quake is the big project at id Software at the moment, and he
  didn't have a lot of time to devote to us. As a result, some items in
  this file are strictly conjecture, regardless of how carefully they were
  tested. Please see section 5 if you suspect this FAQ contains erroneous

0D. Where is the latest version of this and other FAQs?

  The latest Doom-related FAQ files and other documents can be found at
  all of the Doom mirror FTP sites. The central location for the Doom
  mirrors is at However, that site is usually quite busy,
  and you may need to locate another mirror site from which to download.
  Listing all the mirror sites is beyond the scope of this document.
  See the 'DOOM: Rec.Games.Computer.Doom FAQ' or 'DOOM: FTP and WWW
  Sites' postings in the* newsgroups for a
  complete list.

  The URL of the directory that contains the Doom FAQ files (usually in
  TXT format, compressed in a ZIP file) is:

  The latest official version of the BFG FAQ is also posted monthly to
  the and .playing newsgroups. This is
  part of the RGCD Periodic Information Postings (PIPs). If your news
  server does not keep the articles long enough for you to find one of
  the PIPs, they are archived at:

  The official location for the hypertext version of the BFG FAQ is
  DoomGate on the World Wide Web. The hypertext version is highly cool.
  Check it out here, along with some other good documents:

-- Section 1 - BFG Basics --------------------------------------------------

1A. What is the BFG9000?

  The BFG9000 (or BFG) is arguably the most powerful weapon in the
  computer games Doom, Doom II, and The Ultimate Doom. It is also the
  most difficult weapon to use well in a deathmatch (multi-player
  competition), because it does not behave in a simple 'point and shoot'

  When you have it in your arsenal, the BFG is selected by pressing the
  7 key on your keyboard.

  When you pull the trigger, there is an excruciatingly long pause as the
  weapon warms up. Then a large green ball of plasma is emitted from its
  barrel. The plasma ball flies in the direction you fired it until it
  hits a target or a wall. Like all weapons in Doom, it will fly straight
  through decorative objects like torches or trees.

  When the green ball hits a solid object, it detonates and does two
  types of damage: Direct Hit and Blast Area. Each damage type is
  outlined in its own section, later in the FAQ.

1B. What does 'BFG' mean?

  The general consensus is that BFG stands for Big Fragging Gun. Well,
  that's the G-rated version at least. That's from Hank Leukart's
  "Official" Doom FAQ.

  The term 'frag' is used in Doom to represent a confirmed kill in a
  deathmatch game. This comes from the idea that in a deathmatch, you are
  killing your fellow space marines. The definition of frag, according to
  the dictionary, is:

    frag Slang. Verb, transitive
    fragged, fragging, frags
      To wound or kill (a fellow soldier) by throwing a grenade or
      similar explosive at the victim: "He got fragged. Blown away"
      (Bobbie Ann Mason).

  Other good name suggestions that have found their way to the authors
  are "Big Funny Gun" (Chris Somers) and the much more logical "Blast
  Field Gun" (William D. Whitaker). As of this writing, we have not
  confirmed any of these with id.

1C. Where can I find the BFG in the game?

  Listing all the locations that the BFG can be found is beyond the scope
  of this document. For detailed information on the location of all
  weapons, please consult the other FAQ files. Keep in mind that the BFG
  appears more often in deathmatch games than it does in single-player

1D. What is the cheat code for the BFG?

  While you are playing the game, type the keys IDKFA to give your marine
  all weapons, keys, and ammunition. Then press the 7 key to select the

  Note: This cheat code is disabled in multi-player games and single-
  player nightmare-skill games.

1E. Why is the BFG missing in my version?

  If you perform the above cheat correctly, but do not get the BFG, you
  may be playing the shareware version of Doom. You must purchase the
  commercial version of Doom from a retailer or id Software before the
  BFG can glorify your screen.

1F. What's this I hear about the original BFG?

  The current version of the BFG is not the way id's designers
  originally envisioned it. According to a recent thread on the
  newsgroups, the BFG behaved quite differently in a pre-release beta
  of Doom. Several people independently reported this feature:

  Apparently, it worked by shooting multiple streams of different types
  of plasma and fireballs. Because this required an unusually large
  number of moving objects, it tended to slow down the game. Therefore,
  the BFG was redesigned with the invisible blast area that is used

  This may explain why the behavior of the blast area is so unusual.
  It seems that the trace calculations still use some of this old code.
  See section 3A for more information.

  Note: Please don't bug the authors for copies of the Doom beta. We
  don't have one. The information in this section was obtained by
  reading a newsgroup thread.

-- Section 2 - The Direct Hit ----------------------------------------------

2A. What is a direct hit?

  A direct hit happens when the BFG's green plasma ball directly hits a
  target. The target can be a monster, an exploding barrel, or an opposing
  player in a multi-player game.

2B. How much damage does a direct hit do?

  A direct hit with the BFG will cause a random amount of damage between
  100 and 800 points. Keep in mind that these are the base values as
  stored in the game engine. The actual amount of damage taken by a
  player is modified depending on skill level. How much is it modified?
  We don't know.

  A note about skill levels: Testing seems to show that weapons always
  do the same amount of damage to monsters, but that the player objects
  can absorb the weapons better at lower skill levels. Therefore, it
  takes more shots to kill a player at lower skill levels, and fewer
  shots at higher skill levels. This is why some players prefer to
  deathmatch at the higher skill levels: The frags are quicker that way.

  If your target is lucky enough to survive a direct hit, he is still
  susceptible to damage from the blast area. This happens sometimes in a
  deathmatch. Since there is a brief pause between the direct hit and the
  blast area calculation, your victim may go through several stages of
  fear and elation in the space of one second:

    1) Victim sees the BFG coming towards him (Uh-oh.)
    2) BFG scores a direct hit (D'oh!)
    3) Victim realizes he has miraculously survived (Woo-Hoo!)
    4) The flash damage kills him a moment later (D'oh!)

2C. What are the limitations of a direct hit?

  The direct hit is not limited by the same parameters as the blast area.
  There is no range limit, and the damage does not decrease with distance.

  The hard part is that the BFG's plasma ball travels at a fixed speed,
  and can be avoided by an alert deathmatch player. The reference number
  for the BFG ball's speed, as stored in the .EXE file, is 25. For
  comparison, rockets travel at 20 and plasma gun shots travel at 25.

  If it seems like this is too fast, and would not be easy to avoid,
  remember that the plasma gun fires in a continuous stream. The BFG can
  only be fired once every few seconds. The BFG's green ball is also very
  bright and large on the screen. All of those factors make it generally
  easier to avoid in a deathmatch game.

  A direct hit in a deathmatch (against good players) is usually the
  result of luck, or the result of a player that did not know the BFG ball
  was coming towards him. See section 4 for details of a trick that can
  help you achieve the latter scenario.

  The direct hit can only damage one target. If there are two targets
  very close together, the green ball can only hit one of them directly-
  whichever one it touches first.

-- Section 3 - The Blast Area ----------------------------------------------

3A. What is the blast area?

  After the green plasma ball detonates, and after the damage is
  calculated and deducted from the target that received the direct hit (if
  any), the area effect of the BFG is calculated. Targets that fall within
  a specially defined area will take varying amounts of damage.

  Simply put, the blast area is like an imaginary 'cone' or 'fan' of 20
  damage traces that briefly extends outward from the attacking player.
  The cone always points in the direction that the weapon was fired. For
  instance, if you originally fired the weapon in the northwest direction,
  the cone will always face northwest, regardless of which direction
  you're facing at the moment of detonation.

  Note that this does not mean that the attacker must continue to face in
  that direction. The attacker is free to turn away from his targets, as
  long as he moves to a position that keeps this imaginary cone pointed at
  them. Common misconceptions are that you must be facing either the
  targets, the detonation point, or the same direction as the weapon was
  fired. None of those things are necessary in order to inflict damage.

  Also note that this imaginary cone has no relation whatsoever to the
  detonation point. The location of the detonation point is only important
  for the direct hit (see section 2). Only the moment of detonation is
  important, not the location. It is possible to have the green ball
  detonate twenty miles away in a completely different room at a totally
  different altitude, but the blast can still cause damage right next to

  The paragraphs above cover the basic concepts of the blast area. More
  detailed information can be found in section 3D, below.

3B. How much damage does the blast area do?

  The 20 traces that make up the blast area's damage cone each do a
  random amount of damage between 5 and 15 points. Again, these are only
  the base values stored in the game engine, and may do different amounts
  of real damage at different skill levels. See section 2B for more info.

  Because these traces radiate outward from the attacker in a fan shape,
  a target will more likely be hit by a given trace if he is close to the
  attacker. Therefore, targets closer to the attacker will generally take
  more damage because they are hit by more traces.

  If a target is very close to the attacker (for instance, standing right
  next to him), the target might be within the hit range of all 20 traces.
  The amount of blast area damage in this situation would be between 100
  and 300 points. However, all 20 traces would not necessarily be absorbed
  by that target, and might move on to other targets. See section 3F,
  below, for more information on this phenomenon.

  This blast damage is calculated in addition to the direct hit damage (if
  any), making the total possible damage points for the BFG a whopping
  1100 points.

  A note about random numbers:

  A phenomenon known as the 'bell curve' happens when you combine the
  outcome of multiple random numbers. Players of book-and-paper role-
  playing games may recognize it. In those games, you would often use
  three dice to generate a random statistic. In theory, adding the three
  dice would generate a random number between 3 and 18. But in reality,
  the actual results would be weighted towards the middle of the range,
  around eleven. The odds of getting a three or an eighteen are rare
  because you'd have to roll 1+1+1 or 6+6+6. There's only one possible
  combination for each outcome. On the other hand, rolling an eleven is
  relatively easy: 6+4+1, 5+5+1, 3+3+5, etc. If you were to graph the
  outcome of a thousand rolls, the graph would be shaped like an arc or
  a bell, with more rolls coming up in the middle of the range of
  possible values. Hence the name 'bell curve'. The role-playing games
  use this to make certain random statistics more fair.

  This applies to the damage traces, as well, because they are
  essentially a group of multiple random numbers. For instance, if you
  hit your victim with all twenty traces, the possible damage should be
  between 100 and 300 points. But the odds are that the total damage
  will more likely be around 200 points, due to the bell curve. The odds
  of doing 100 or 300 points damage in that situation would be extremely

3C. How long does the blast effect last?

  Testing has shown that there is a brief time window in which a hapless
  player can wander into the damage cone after detonation and still take
  some blast damage.

  There seems to be two factors at work here:

  1) There is a brief pause between the moment of detonation and the
     moment that the damage traces begin to work. This pause seems to
     have been inserted deliberately by the designers. The exact
     duration of this pause is not known. Some evidence suggests that
     the pause is about four-tenths of a second long, but this is not
     confirmed. It's not known exactly how it affects the trace
     calculations, but it seems as though all calculations begin
     -after- the pause.

  2) It seems as though the traces are not calculated instantly. If a
     player moves into the damage cone during the trace calculations
     (after the deliberate pause), he might still take some damage. At
     the time of this writing, the exact duration of the calculations
     has not been determined. It is possible that the trace calculations
     work more slowly when there are many things happening in the game,
     i.e., when there are a lot of monsters on the screen. However, this
     has not been confirmed, and we might even be imagining the whole
     thing. It's possible we're mistaking this for the deliberate pause
     mentioned above. This question will hopefully be addressed in more
     detail in a later version of this FAQ.

3D. How exactly does the blast area work?

  The blast area is a spread of 20 invisible traces that radiate outward
  from the attacking player. The damage for the traces is calculated
  shortly after the green ball detonates against a target or a wall.

  The traces radiate outward in an imaginary cone that is roughly as wide
  as the player's view, i.e., about 45 degrees to either side of the
  centerline. The cone always points the same direction as the attacker
  was facing when he fired the weapon. For instance, if you fire the
  green ball in the southeast direction, your cone of traces will always
  radiate towards the southeast.

  Regardless of how much you run and turn between the time you fire and
  the time the green ball detonates, the traces will always radiate from
  your location. Think of it like a tank with a gyroscopically stabilized
  turret: only the cone's origin point moves around with you, not its
  direction. The cone's direction remains fixed on the same compass

  From a technical point of view, the game engine does not actually keep
  track of the cone while you're running around. That's just the effect
  it seems to have. Most likely, it simply stores the vector of the
  direction of the green ball's flight in a variable. When the time comes
  for the ball to detonate, the variable is retrieved to begin the
  calculations for the traces.

  Because of this, the cone's direction is based on the direction that
  the green ball was actually fired, not where you were when you pulled
  the trigger. As far as the game engine is concerned, you haven't fired
  it until it actually leaves the barrel of the gun.

  Here's a diagram of how it works:

        * <- Blast
             detonates         \   Damage  /
             here               \   Cone  /
                                 \       /
        ^                         \     /
        |                          \   /
        |                           \ /
        X          X -->             X
    Attacker      Attacker       Attacker
    fires BFG     runs east      is here at
    northward                    detonation

  Note that this diagram is foreshortened. The detonation point would
  have to be quite far away in order for the attacker to run that far.
  But the principle is the same, regardless of how far the green ball
  flies: The damage cone is calculated after the green ball detonates.

  When the green ball detonates, the traces are calculated one at a time,
  using the same criteria for calculation that the engine might use for a
  bullet: If there is a solid object (a wall, etc.) between the target
  and the attacker, the trace is harmlessly absorbed by the object. With
  one exception: In order to hit a target with a bullet, you had to be
  facing the target. You don't have to be facing your target in order to
  do damage with one of the traces.

  Quick review:

    - The cone of traces always points in the same compass direction, the
      direction you originally fired the BFG.

    - You sort of 'carry the cone around' with you as long as the green
      ball is still flying.

    - When the green ball detonates, the cone of traces does its damage
      depending on where you're standing at that moment, and who is in
      the cone.

    - You do not have to be facing the targets to do damage, you only
      have to maneuver into a position where the cone is pointing at your

3E. What are the limitations of the blast area?

  There is no range limit for the blast area, but the farther a target is
  from the attacker, the less of a chance it will be hit by a given trace,
  therefore the less damage it takes.

  Because of this, the effective range of the blast area ends up being in
  the neighborhood of 1000 units. At the outer edges of this range, a
  deathmatch opponent will only get hit by one trace, taking only 5-15
  points of damage. Farther out from that range, it becomes increasingly
  unlikely that a target will be hit by any traces at all. Of course,
  larger targets such as spiderdemons have a wider radius, and therefore
  the BFG's effective range is slightly farther against such targets.

  Keep in mind that there is no part of the program that explicitly
  prevents traces from hitting targets outside the 1000 unit range. It
  can happen, and does in fact happen, it is simply less likely. For the
  purposes of learning how to use the weapon in a deathmatch game, base
  your strategies on the idea that its main effective range is about 1000
  units, and you'll be OK.

  If you are unfamiliar with the Doom engine's units, remember that a
  standard teleporter pad is 64 units across. Line up 16 of those and
  you've got a basic idea of what 1000 units is.

  The blast damage is also limited to targets that have an unblocked
  line of sight to the attacking player. This does not mean the attacker
  must see the target. It means that the attacker must be in a position
  where his traces can see the target, i.e., he could see the target if
  he were facing in that direction.

3F. How many targets can it hit?

  The blast area can only hit as many targets as its traces can touch.
  Since one trace can damage more than one target, you can theoretically
  kill more than 20 targets. In tests on an artificially created grid of
  monsters, it is not uncommon for a single shot to kill 25 imps. But in
  regular game play, rarely are that many targets standing in such a
  perfectly aligned pattern. Usually, some individual targets will soak
  up more than one trace, while other traces miss targets completely.

  The traces are calculated on a 'first come, first fragged' basis. For
  each trace, the damage is calculated and subtracted from the target and
  the trace. Where applicable, any target that dies from the trace is
  removed from the map. Then the engine moves on to the next target in
  the line of that trace. When the trace runs out of damage, the
  calculation routine moves on to the next trace.

  Here is how it works:

  (Please note: In the discussion below, we refer to 'line of sight'
  loosely. Remember that the attacker does not need to be looking at his
  targets to inflict damage.)

  In the following scenario, imagine that the attacker is standing in a
  direct line with several targets (imps, perhaps) lined up in front of
  him, and the green ball detonates on a wall somewhere:

  Attacker:  X->         X X X X X X X       Detonation point: X

  The first couple of imps are close to the attacker. They crumble,
  having soaked up some of the traces that are pointing ahead of the
  attacker. The next few imps are a little farther away, and absorb some
  more of the traces, but not as many. They absorb fewer traces for two
    1) because the imps in front of them absorbed some of them
       already, and
    2) because they are farther away and the traces are more
       spread out.
  But they still die. The next imp gets damaged, but does not die. He
  has soaked up the last trace that was headed in that general direction.
  The last imp is not damaged at all because there are no more traces
  left in his direction.

  In order for the above scenario to work, the targets must be perfectly
  aligned. For instance, in the following scenario, all of the targets
  take full damage, because there's no one in front of them to soak up
  Attacker:  X->            X                      Detonation point: X
                          X    Y

  The one target in the back (Y) is still susceptible because it is not
  blocked by another target. The attacker can see him through the gap.
  So, for example, an imp standing directly behind a cyberdemon is
  fairly safe, but an imp standing next to a cyberdemon is a sitting

  The moral to this story is: In deathmatch, do not depend upon other
  players or monsters to absorb the BFG blast unless they are exactly
  between you and your attacker. And you'd better hope they're very
  healthy. In all other cases you take full damage.

3G. How does altitude affect it?

  For the most part, it does not. With a few exceptions.

  Again, in the discussions that follow, we refer to 'line of sight'
  loosely. You do not have to look at your targets to hit them.

  If a difference in altitude brings your target out of the sight of your
  traces, then yes, it makes him safe from the blast damage. But if your
  traces can see any part of him, he takes full damage regardless of how
  much higher or lower you are than he is.

  As far as altitude is concerned, the traces seem to use the same
  criteria as your view does to determine if the target is visible. In
  other words, if both you and the damage cone are facing the target, but
  the target is above the top of the screen, you can't hit him.

  But there is a catch. The upper and lower angle limit of the traces
  seems to be the same as your view would be if your screen was fully
  zoomed in. For instance, if you are displaying the status bar at the
  bottom of the screen, your view window is slightly cut off at the top
  and bottom. Press the plus (+) key repeatedly to zoom all the way in,
  and you can see what this means. The BFG's traces seem to use the same
  angle as this full view does to determine if they can hit the target.
  So if you've got the status bar showing, you can actually hit someone
  who is off the top of your screen. If you are fully zoomed in, your
  view seems to be an accurate representation of the damage cone's angle.

  If you are standing on a ledge above your target, and you are so close
  that you can 'touch' him (i.e., you can't step off the ledge because
  you're bumping into him), your shots will go right over his head and
  the blast damage will not affect him. This is because, technically, the
  traces can't see him. Well, if you could look down you would see him,
  but you can't look down in Doom. Must be those darned restrictive space

3H. If I am only partially exposed, do I only take partial damage?

  No such luck. The only thing that reduces your damage is getting hit
  with fewer traces. Here is how it works:

  If you are hiding behind a decorative sprite (such as a tree or a
  technical column) you are fully exposed. All weapons in Doom always
  pass completely through decorative sprites.

  If you are peeking over a podium, or partially obscured by a raising
  lift, or a closing door, and only half or one-tenth of you is showing,
  you still take the full amount of damage. The traces are calculated
  based on the game's two-dimensional block map. As far as the game
  engine is concerned, all of the traces can still hit you.

  If you are hiding behind a vertical wall with your rear end peeking
  out, you might take a little less damage because some of the traces
  may hit the wall instead. But don't count on it. Tests seem to show
  that your distance from the attacker is more important than how much
  of you is exposed. This is an observed phenomenon, not necessarily
  supported by hard facts. It is difficult to test due to the random
  nature of the damage traces.

  Also remember that what counts as 'showing' may not be what you think.
  The Doom engine uses the radius of the player to determine visibility.
  Your player's aspect ratio does not change when you rotate. It also
  seems as though your radius is slightly larger (in some cases) than
  the sprite (picture) that represents your player. In tests, it is
  possible to inflict damage upon a player that seems to be out of sight
  (no visible pixels) but whose radius is large enough to count as
  'visible' to the BFG traces.

3I. What happens if the attacker is fragged before detonation?

  The BFG's traces are still active, even if the attacking player is
  dead. So if you fire the BFG, then get fragged, do not press the space
  bar to respawn your marine right away. Wait until the green ball has
  detonated before you respawn.

  Here's why:

  Even after being fragged, you can still see the action from your fixed
  point of view on the ground (your 'dead' state). The traces remain
  active and can still frag an opposing player (hopefully the one that
  fragged you). The traces will radiate from your dead body's 'eyes'.
  The traces still follow the same rules, i.e., they radiate in the
  direction the green ball was fired, regardless of which direction your
  'dead view' is facing.

  In a previous version of this FAQ, we reported that you will lose
  the chance to frag your opponent if you respawn before detonation.
  Several people pointed out to the authors that the statement was in
  error. The traces remain active even after respawning. Testing shows
  that the traces do, in fact, continue to radiate from the dead body
  even after you have respawned in a completely different area of the
  map. This testing was performed at the prompting of Kirby Nixon, who
  insisted that it was true. Whaddya know? He was right.

  This means that, technically, you don't need to hang around and watch
  your opponent in order for the traces to work. But Kirby pointed out
  a good reason to wait for the detonation before respawning: Your dead
  body's traces can frag you, too! Just because they were once your
  traces doesn't mean you're immune. If you are unlucky enough to
  respawn within your dead body's damage cone, you can kiss your butt

  Of course, the same thing applies to projectile weapons like the
  rockets and the green ball. It has long been known that those items
  behaved in that way. But this information about the damage traces is,
  to the authors' knowledge, new.

  Please note: Any projectile kills made by a respawned player (whether
  by rockets, plasma, BFG traces, etc.) do not contribute to that
  player's frag count. Killing -yourself- in this manner does not change
  your frag count, either. This appears to be because the game engine
  creates a new instance of the player-object at respawn-time, and
  therefore 'forgets' to award that frag. In any case, if you wait
  before respawining, you will get credit for the frag as long as you're
  still dead. This is another reason to wait for detonation before
  respawning. Special thanks to John Castelli for pointing this one out.

3J. What about multiple BFG shots?

  Each BFG shot is tracked and calculated independently. Testing seems
  to indicate that the game engine's code is object-oriented, and has no
  trouble keeping track of multiple blast areas. Each damage cone's
  direction is based on the direction of its corresponding green ball.
  The origin point of the damage cone is based on the current location
  of the marine who fired it (even if that marine is just a dead body-
  see section 3I for more info).

-- Section 4 - Deathmatch Techniques ---------------------------------------

4A. What is considered unfair when using the BFG?

  Many deathmatch players moan and groan when the BFG is used successfully
  against them. 'What a cheap frag, you craven coward!' they shout. Well,
  they usually use fewer words to express the idea, but that's what they
  mean. This is usually due to a lack of understanding about how the
  weapon works.

  The purpose of this FAQ is to educate players about how the BFG behaves.
  If you know how it works, you will know how to defend yourself against
  it. You will also know how to effectively attack with it. If both (or
  all four) players have the same knowledge about how the weapon
  functions, then the BFG by definition is not unfair. If you play against
  an opponent who does not know how the BFG works, then you should make
  sure to educate them on its behavior before turning them into paste.

  Having said that, the following things are debatable regarding fairness.
  I'm not saying they are patently unfair, I'm just saying that their
  fairness is debatable:

  - The Silent BFG trick (see section 4D).

  - 'Sitting on' or 'guarding' the BFG when you are playing deathmatch
    2.0, and picking it up again every time it reappears.

  - Having a BFG left over from a previous level when there is no BFG
    available to the other players on the current level.

  In the last two examples, four-player deathmatch tends to cancel out
  any advantages to those techniques. The remaining three players usually
  coordinate and attempt to bring down the king of the hill in these

4B. What is the best way to defend against the BFG in a deathmatch?



  This requires, of course, that you know where the cone of damage
  actually is. That, in turn, requires that you know where your attacker
  is and in what direction he fired the weapon. That, in turn, requires
  that you know the weapon was even fired at all. Which, in turn, may be
  difficult against a player who has mastered the Silent BFG trick
  (See section 4D).

  It still helps if you are playing the game with a stereo sound card
  and headphones. This allows you to hear how far away and in which
  direction your opponents are. If you think in three dimensions, the
  sounds you hear in the game will give you a great tactical advantage.

  You must understand completely how the weapon works before any
  avoidance technique would be meaningful. So if you skipped ahead to
  this section, go back and read the gory details.

  With all that said, here are a few ideas. These are just things to
  try, not necessarily good things in all cases.

  - Run past the attacking player so that you end up behind him. This
    assumes that he is still facing the same direction as his damage
    cone. You will be completely safe if you're on the opposite side
    of his cone. This can backfire if you're not careful. You could end
    up three feet from him and inside his cone when the green ball
    detonates, and soak up some rays. Twenty of them, to be exact. That
    SPF 60 sun block won't help, either.

  - If you think you're about 1000 units away from the attacker, and
    you don't think he's running towards you too fast, you can try
    running away, and hope that the traces will be too thinned out to
    damage you seriously.

  - You can duck behind a nearby wall or a solid column. If you can see
    your attacker, simply move so the column is between you and him.
    Wait for the blast to detonate and die down, then step out from the
    column and place some ordnance in his face. This technique works
    well on Doom II's 'Circle of Death' level (11).

  - If you are very close to him, you can attempt to frag him before his
    shot gets off. When he pulls the trigger, there is a slight pause
    while the weapon warms up where you can still stop him dead in his
    tracks. There is nothing more exhilarating than hearing his BFG
    spinning up, then the sound of his scream as your super shotgun
    removes his face. Muahahahaha...

  - If you are involved in a turning, running, spinning melee in an open
    area, keep it up. Learn how to circle-strafe (use a combination of
    mouse and keyboard controls to turn, run, and strafe all at the same
    time). If you keep your attacker running in circles, his cone of
    damage will hardly ever be pointing at you. He will eventually run
    out of ammo, or you will frag him with conventional firepower. This
    technique works well in the main courtyard of Doom II's 'Citadel'
    level (19). In this kind of melee, it is nearly impossible to keep
    track of the cone (for either you or your attacker), so you are
    really taking a gamble that the turning fight will be to your
    advantage. But the exhilaration of winning that kind of fight is one
    of the best rushes you can get.

  - If you are well armed and very healthy, you can judge whether or not
    you can survive a blast area hit at your current distance. Then take
    advantage of the fact that he's trying to keep you in his sight. He's
    got a moment or two where he must leave himself exposed while he
    tries to soak you with his traces. Pepper him with rockets or plasma.
    Grit your teeth and take the blast area hit, but keep on him. Just
    don't get too close.

  - Anything else that takes advantage of the particular quirks of the
    weapon. Remember that you can use your knowledge of BFG attacking
    techniques to your advantage, like the example above.

4C. What is the best way to attack with the BFG in a deathmatch?


  (Sha, nice try.)

  This requires, of course, that you know where the cone of damage
  actually is. So if you looked here first, go back and check out the
  rest of this FAQ for details.

  Anyway, here's some ideas. Not necessarily comprehensive:

  - The best universally accepted method is to shoot a wall or solid
    column that is very close to you. In this situation, your cone of
    damage roughly equals the visible targets on the screen. This is
    because you don't have much time to move around before detonation.
    Your targets don't have much time, either (You will notice that all
    of the 'defense' tips in this FAQ assume having time to react).
    Because we already know two things:
       1) The direct hit is difficult to achieve,
       2) The location of the detonation does not matter,
    there is no reason to try shooting the green ball at your targets.
    Your goal is to get the green ball to detonate as quickly as
    possible after you decide upon your targets. Just make sure you're
    facing your targets when you fire. If you have to rotate away from
    the direction of fire in order to see your targets, your cone of
    damage may not hit them.

  - The next best thing is to use the strafe feature heavily. Don't
    rotate, just keep strafing and keep your targets in sight while you
    wait for the detonation. This also keeps your cone of damage roughly
    lined up with your view, allowing you to use your view as a
    reference. If your targets are trying to run behind you to get behind
    your damage cone, running backwards while strafing may also help.

  - Combine the two previous attack methods: Shoot a nearby wall, then
    strafe toward your targets. This takes advantage of the pause that
    happens after detonation. You have a few heartbeats before the traces
    are calculated, so use this time to strafe your targets into view.
    The best example would be at a 90 degree hallway intersection: Shoot
    the wall at the corner, then strafe out into the hall. This is really
    just a shortened version of the level one strafe trick, except you
    don't have to wait for detonation.

  - "Everything I need to know, I learned at Top Gun." Avoid turning
    fights. See the related item under the defense techniques, above.

  - "Keep your friends close, but keep your enemies closer." Really. The
    closer you are, the more traces will hit their faces. Don't even
    bother firing if your opponents are more than 1000 units away: you
    will either miss, or do very little damage.

  - Don't be afraid to use it in close quarters. You might think the BFG
    is designed for open-area use, but it actually works best when things
    get cramped. The 'shoot the wall' trick really mulches 'em in a
    narrow hallway.

  - Keep it loaded, then use it liberally. Find lots of ammo for it. Use
    a backpack to double your ammo capacity. Then shoot it off whenever
    you get the urge. For instance, every time you enter a new room or
    open a door.

  - Set up pre-timed shots that take advantage of its long warm-up time.
    Like this: pull the trigger, *then* open the door. Or pull the
    trigger, *then* drop off the ledge into the room with your target.

  - Shoot the green ball at a very distant wall (such as outdoors or
    down a long hallway), then run into the room where your target is.
    He may not know you even fired, or he may think it already detonated.
    Either way, you can just stand there. When the ball eventually
    detonates, your target will simply see himself crumble to the ground,
    realizing too late that you were standing still because you were
    keeping your traces on him. See section 4E for an example of this.

  - Use 'combo' moves. Use the above 'distant wall' technique, but switch
    to a conventional weapon as you run into the room. Your traces still
    work, even if you have switched weapons. Blast 'em with both the BFG
    traces and something else at the same time. Special thanks to Dan
    Christensen for this suggestion.

  - Bait your prey. Use the above 'distant wall' technique, but switch to
    the pistol and fire it while running into the room. They will hear
    your pistol and attempt to get very close to frag you. If timed
    correctly, they will be right in your face at detonation time. Splat

4D. What is the Silent BFG trick?

  Defending yourself against the BFG pretty much depends on your ability
  to know precisely when it is being used against you.

  If you are fortunate enough to play deathmatch with a stereo sound card
  and headphones, you know that sound cues are vital to playing well in
  deathmatch. In many cases, the only way a potential victim knows the
  green ball is in the air is by the distinctive sound the weapon makes
  when fired. The headphones can give him directional cues as to its
  origin, and therefore point the way towards a proper escape.

  So if you wish to get the drop on someone, wouldn't it be great if you
  could put a silencer on that weapon? Well you can. A limitation in
  Doom's sound code allows you to silence the firing sound of the BFG.
  Regardless of the 'Number of Sound FX to Mix' that you chose in Doom's
  setup program, your character can actually only utter one sound at a
  time. This includes all weapons firing. If you cause your character
  to grunt, i.e., you jump off of a ledge or press the space bar on a
  blank wall, you have a brief period while the grunting sound is being
  played in which you can pull the trigger and no sound will be emitted
  from the weapon. Your grunt makes a little noise, but it's relatively
  quiet and is sometimes ignored by your opponents.

  While it works well in theory, in practice the trick is hard to
  perform. It also may be a little unfair. As with all secrets, it
  definitely makes the game unfair if you don't share this information
  with your opponents.

  As of this writing, there seems to be a small handful of players on
  the doom newsgroups who use this trick. The first person to submit
  this trick to the author of this document was John Fedor.

  Interesting anecdote: When reviewing a draft copy of this FAQ,
  American McGee at id Software informed us that they have been using
  the Silent BFG trick in their deathmatch games since day one.

4E. What is the Level One Strafe trick?

  The level one strafe trick is not a deathmatch technique per se, but
  it's a demonstration of the BFG behavior that educates many folks on
  how the BFG really works. The act of performing this trick tends to
  open one's eyes to the amazing possibilities of the weapon. It also
  proves some points made in this FAQ.

  Doug Bora first pointed this demo out to our particular group. Credit
  for the original version of this demo goes to John Ripley of the UK.
  The full deathmatch demo file PETALK2.ZIP is the first example of this
  specific action. This file should be available at:

    ftp://{INS site}/lmps/doom2/1.9/
    where {INS site} = any DOOM ftp site, eg.

  Since that time, this has been repeated by many folks on the Doom

  How to do this:

  - Set up a deathmatch game with Doom II, starting on level one, no
    monsters, deathmatch 2.0, ultra violence skill level.

  - Player one (Green) will most likely appear on the ledge with the
    chainsaw, BFG, rocket launcher, and super shotgun. Tell him to move
    so that he is within view of that first entrance room, standing on
    the ledge where he can see down the brightly lit hallway from his
    perch above the brown room. Tell him to sit tight right there. He is
    frag bait for this demonstration.

  - Player two (whoever) will stroll into the brown room and pick up the
    BFG behind the column. Wave to the nice guinea pig waiting patiently
    on the platform above. (Hi Phil. Hi Ralph.)

  - Player two strolls down the brightly lit hallway to the intersection
    where he can see the other dark room, way down the long hallway. You
    can just make out the plasma gun sitting on that podium in there.

  - While facing the plasma gun from the intersection in the bright
    hallway, fire the BFG. When the shot actually leaves the barrel of
    the gun and begins traveling toward the plasma gun, strafe quickly
    back toward the intersection where you can see Greenie standing on
    the ledge in the first brown room.

  - If you reached that hallway intersection in time (before the green
    ball detonated in the plasma gun room) you will be rewarded with
    seeing the frag bait get fragged. Well, at least damaged. Maybe

  - One extra credit point to anyone who guessed that you don't have to
    be facing Green Boy to kill him. You just have to make it to that
    intersection in time. You could be turned completely away from him,
    he will still be hit by the traces. You can prove this by running
    straight to the intersection rather than strafing to it.

  This demonstration proves the following:

  - You don't have to be anywhere near, or even facing the detonation
    point to damage your targets. You only have to move to a position
    where your cone of traces is on them.

  - The cone of traces always points the same direction regardless of
    which direction you turn.

  - You do not have to face your targets in order to hit them.

  - You can fire the BFG in a totally different area than where you want
    your targets to be damaged.

  Players who perform this stunt successfully the first time are usually
  amazed that it actually works. This is also a good practice for using
  similar moves in real deathmatches.

-- Section 5 - Submitting Corrections --------------------------------------

5A. Common misconceptions

  This is a list of the most common misunderstandings about the behavior
  of the BFG. Please review this list before submitting corrections.

  1) You have to be looking at your target in order to inflict blast area

     This is untrue. The target must be within an imaginary line-of-sight
     to you at detonation time, but you can be facing away from the
     target, provided it meets all the other criteria.

     This is an easy mistake to make because you tend to be more accurate
     in positioning your cone of damage if you keep your eyes on your
     targets. Especially if you are strafing instead of rotating.

     See section 4E for proof of this.

  2) You have to see the detonation point in order to inflict blast area

     Nope. The detonation point can be completely out of your range of
     sight, and can be separated from you and your targets by a hundred
     solid stone walls.

     Again, see section 4E for proof of this.

  3) The location of the detonation point is a factor in the blast damage
     area calculations.

     Only the moment of detonation is important. The location of the
     detonation point is not used. See number 2, above.

  4) The location you were standing when you fired, or the location of
     targets at firing time, is a factor.

     Only the location where you are standing when the blast detonates is
     important. The compass direction that you fired is important, but
     not the location where you fired. The traces are only calculated at
     detonation time. The game engine does not care where the targets are
     until the traces are calculated.

     Again, see section 4E for proof of this.

  5) You have to be facing the same direction at detonation time as you
     were at firing time.

     No, the cone of traces extends outward in the same compass direction
     regardless of which way you are facing at detonation time.

     Again, an easy mistake to make because you tend to be more accurate
     if you keep your eyes on your targets. Again, especially if you are

     Again, see section 4E for proof of this.

  6) Your BFG blast can frag someone behind you, but only if they are
     close enough to touch you.

     You can frag someone behind you if they fall anywhere within the
     cone of traces. Sure they can be behind you, but they don't have to
     be touching you. In order to frag someone behind you, you must
     rotate away from the direction you fired, then maneuver so that
     your targets are within the cone behind you.

     Having said that, if the victim is standing right next to the
     attacker, at 90 degrees perpendicular to the cone of damage, they
     will fall within the cone if they are in front of the attacker's
     centerline. But if they are truly behind the attacker's cone of
     damage (behind the centerline of the attacker), they will walk away

     This seems to be due to the fact that the player's 'hittable'
     radius is larger than the player's 'walk into' radius. When you
     walk up to a player and bump into him, his 'hittable' area is
     overlapping into your area.

     This is an easy mistake to make when looking at a deathmatch game,
     where everyone is moving around each other so quickly that it's
     hard to keep track of the location of the cone of damage. If you
     really think you fragged someone behind you, it's probably because
     of one of two reasons:
       1) They were actually next to you and slightly forward of your
       2) You rotated away from the direction of fire, and the victim
          stepped into the cone of damage that still existed behind you.

5B. I think the FAQ is in error. How do I get it corrected?

  Please go through this checklist before submitting information:

  1) Read the entire FAQ to be sure we did not cover your point in
     another section. Check the 'Common Misconceptions' section, above,

  2) If you have a theory about the BFG behavior, please test it
     carefully before submitting it. If you can't reproduce the effect
     under controlled conditions, you were probably witnessing a side
     effect of one of its known behaviors. Or perhaps it happened in a
     deathmatch game, where the action is so fast that you often can't
     keep track of what's going on.

  3) If you think you have tested your theory thoroughly and are ready
     to submit the theory as proven, please prepare a short description
     statement that details how to reproduce the effect during game play.
     Please make sure the description is short and precise.

  4) When you have composed your description message (please make it as
     short as possible), e-mail it to and wait patiently
     for a reply.

  5) Note: Do not attempt to send us information for FAQ files other than
     this one. We do not maintain other FAQ files and we do not echo
     information amongst other FAQ authors.

============================ End of BFG 9000 FAQ ============================

sconceptions' section, above, too. 2) If you have a theory about the BFG behavior, please test it carefully before submitting it. If you can't reproduce the effect under controlled conditions, you were probably witnessing a side effect of one of its known behaviors. Or perhaps it happened in a deathmatch game, where the action is so fast that you often can't keep track of what's going on. 3) If you think you have tested your theory thoroughly and are ready to submit the theory as proven, please prepare a short description statement that details how to reproduce the effect during game play. Please make sure the description is short and precise. 4) When you have composed your description message (please make it as short as possible), e-mail it to and wait patiently for a reply. 5) Note: Do not attempt to send us information for FAQ files other than this one. We do not maintain other FAQ files and we do not echo information amongst other FAQ authors. ============================ End of BFG 9000 FAQ ============================