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              DOOM II (DOOM 2: HELL ON EARTH)

                     GAME SOFTWARE FOR
        IBM-PC, APPLE MACINTOSH AND OTHER COMPUTERS

                     GHOST-MONSTER FAQ

                    REVISION 01/14/2000

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0. Introduction
1. What Is A "Ghost" In Doom II Games?
2. Where Can I Encounter Ghosts?
3. Which Monsters Can/Cannot Become Ghosts?
4. Can The Ghost Effect Occur Any Other Way?
5. What Affects A Ghost's Movement?
6. How Can Ghosts Be Killed?
7. Can Ghosts Be Resurrected Again?
8. What Happened To The Ghost I Saw?
9. Will A Surviving Ghost Affect My Score?

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0. INTRODUCTION
===============
o This document provides general information on a bug that
  occasionally surfaces in computer-based Doom II games:
  The creation of a "ghost" by an Arch-Vile monster.

o This document primarily refers to the software package
  "Doom 2: Hell On Earth", version 1.9.  Other Doom II
  games which are not addressed here (such as Final Doom)
  may be included in future updates.

o This document is 59 characters wide, and is best viewed
  in a monospaced-font format.

1. WHAT IS A "GHOST" IN DOOM II GAMES?
======================================
o A "ghost" is an abnormal Doom II monster.  It can move
  freely through some solid surfaces, and is immune to a
  wide variety of attacks from players and other monsters.

o A ghost is created when an Arch-Vile resurrects the
  crushed corpse of a monster.  (Corpses are often crushed
  by closing doors, or crushing ceilings or pillars.)

2. WHERE CAN I ENCOUNTER GHOSTS?
================================
o Ghosts may never be encountered during normal game play.
  The chart below indicates map levels where ghosts can
  conceivably be generated during a normal Doom II game.

o Map levels where ghosts may be created in Doom II v1.9:

                         | Skill | Skill
  Map | Map name         | 1/2   | 3/4/5
  ----|------------------|-------|------
  .11.|.CIRCLE OF DEATH..|.Yes...|.Yes..
  .14.|.THE INMOST DENS..|.No....|.Yes..
  .16.|.SUBURBS..........|.No....|.Yes..
  .20.|.GOTCHA!..........|.Yes...|.Yes..
  .25.|.BLOODFALLS.......|.Yes...|.Yes..
  .27.|.MONSTER CONDO....|.No....|.Yes..
  .28.|.THE SPIRIT WORLD.|.Yes...|.Yes..
  .29.|.THE LIVING END...|.Yes...|.Yes..
  ---------------------------------------------------------
  Notes: In PC Doom II, map 11 is referred to as "CIRCLE OF
  DEATH" in the tally screens, and "'O' OF DESTRUCTION!" in
  the Automap.
  Map 17, "TENEMENTS", and map 23, "BARRELS O' FUN", are
  not included here, because any Arch-Viles on those maps
  cannot gain access to areas where monster corpses can be
  crushed.
  Map 30, "ICON OF SIN" is not included here.  Although
  Arch-Viles may be generated by the Boss entity on this
  map, monster corpses on this map cannot be crushed.

3. WHICH MONSTERS CAN/CANNOT BECOME GHOSTS?
===========================================
o The following monster types can be resurrected as ghosts
  in Doom 2: Hell on Earth:

  Zombieman/Former Human
  Shotgun Guy/Former Human Sergeant
  Heavy Weapon Dude/Chaingunner
  Imp
  Demon
  Spectre-Demon
  Cacodemon
  Hell Knight
  Baron of Hell
  Arachnotron
  Revenant
  Mancubus

o The following monster types cannot be resurrected as
  ghosts in Doom 2: Hell on Earth:

  Lost Soul (leaves no corpse)
  Pain Elemental (leaves no corpse)
  Arch-Vile (cannot be resurrected)
  Spider Mastermind (cannot be resurrected)
  Cyberdemon (cannot be resurrected)
  Map 31/32 "SS Officer" (no Arch-Vile present)
  Map 32 "Commander Keen" (no way to crush, no Arch-Vile)
  Map 30 "Boss" (no way to crush, Arch-Vile cannot access)

4. CAN THE GHOST EFFECT OCCUR ANY OTHER WAY?
============================================
o While playing a computer-based Doom or Doom II game, an
  extremely rare program error, an "all-ghosts bug", may
  occur.  This bug can cause all living things on the
  current map to instantly attain "ghost" status, including
  players and some monster types that normally cannot exist
  in ghost form.

5. WHAT AFFECTS A GHOST'S MOVEMENT?
===================================
o A ghost version of a given monster type will move and
  behave much like the normal version of that monster, but
  with a few exceptions.  Ghosts are immune to some of the
  limitations that affect a normal monster's motion, but
  remain restricted by others.

o The axis of a ghost (an imaginary vertical line running
  through its center) cannot cross through or underneath
  any horizontal surface that is the "top" or "floor"
  surface of a solid structure or object.  (However, this
  can still allow a ghost to move up to half of its body
  into most vertical surfaces and objects.)

o A ghost may move its entire body through or above any
  horizontal surface that is the "ceiling" or "bottom"
  surface of a solid structure or object.

o In general, a ghost can move all the way through any part
  of a structure that has no horizontal surfaces.  This can
  include closed doors, or any wall that stretches floor to
  ceiling (or ground to sky).  If a ghost encounters a
  horizontal surface it cannot cross over or under, it may
  attempt to go around the intervening structure or object,
  rather than through it.

o Sample ghost movement through solid structures/surfaces:

  One solid pillar | Two pillar sections
  -----------------|--------------------
  ____ _ _ _ ____  |  ____ _ _ _ ____
      :     :      |      :     :
  (|)(|)(|) :      |  (|)(|)(|) :
      : (|) :      |      :.(|).:
      : (|) :      |        (|)
      : (|) :      |        (|)
      : (|) :      |       _____
      : (|) :      |      |     |
      : (|)(|)(|)  |      |    (|)(|)
  ____:_ _ _:____  |  ____|_ _ _|____
  ---------------------------------------------------------
  Notes: The first diagram shows one wide, floor-to-ceiling
  pillar; The second diagram shows a similar pillar, with
  its center third removed, effectively making two separate
  structures; A "(|)" represents a ghost Cacodemon.
  The first diagram shows that a ghost Cacodemon can move
  its entire body through any part of this solid pillar.
  The second diagram shows that a ghost Cacodemon can move
  freely through the top section, but can only move about
  half its body into the sides of the bottom section.  (A
  ghost cannot move its axis beneath any horizontal surface
  that is the "top" or "floor" of a solid structure.)

o The axis of a ghost cannot cross through the axis of a
  player or another live monster.  The axis of a ghost also
  cannot cross through the axes of torches, barrels, lamps,
  and similar solid objects.

o Like all walking players and monsters, walking ghosts are
  limited in how high they can climb when taking a single
  step.  If a normal monster is unable to climb up onto a
  structure, then the equivalent ghost monster will also be
  unable to climb onto that structure.

o Walking ghosts are not inhibited by steep dropoffs.  For
  example, a normal Imp standing on a high ledge or cliff
  cannot step directly down off the edge; A ghost Imp can.

o Ghosts cannot open doors or activate elevators/lifts.

o Ghosts (and ghost corpses) cannot be crushed.

o Ghosts cannot be teleported.  Ghosts do not respond to,
  or trigger, teleport lines or teleporter pads.

6. HOW CAN GHOSTS BE KILLED?
============================
o The following events/attacks can injure or kill any
  ghost:

  Barrel explosion
  Player rocket explosion
  Imp scratch attack
  Demon bite attack
  Spectre-Demon bite attack
  Lost Soul attack
  Cacodemon bite attack
  Hell Knight scratch attack
  Baron of Hell scratch attack
  Pain Elemental attack (Lost Soul attack)
  Revenant punch attack
  Arch-Vile attack (direct hit or near miss)
  Cyberdemon rocket explosion
  Player teleporting into ghost's coordinates
  ---------------------------------------------------------
  Notes: A rocket will not detonate if it touches a ghost;
  but if the rocket detonates against a solid object, any
  ghost within range of the explosion can be affected.
  A completed Arch-Vile attack affects the target and a
  small area around the target; A ghost can be harmed
  anywhere within this region.
  A ghost can be "telefragged" like any normal monster: If
  a player teleports to a ghost's location, the ghost is
  killed.  Ghosts cannot be telefragged by other monsters.
  Note that normal-monster weapons will auto-aim as usual
  when used on ghost monsters, but player weapons will not.

o As with normal monsters, ghosts can be destroyed through
  the use of "mass-kill" cheat codes.  (Such codes exist in
  Doom 95, and in various third-party "source ports" of the
  original Doom engines.)

o The following events/attacks/projectiles cannot injure or
  kill any ghost:

  Player punch attack (normal and Berserk strength)
  Player chainsaw attack
  Player bullets (pistol and chaingun)
  Player pellets (both shotgun types)
  Player rockets (unexploded)
  Player plasma (plasma rifle and all BFG-9000 emanations)
  Zombieman/Former Human bullets
  Shotgun Guy/Former Human Sergeant pellets
  Heavy Weapon Dude/Chaingunner bullets
  Imp fireballs
  Cacodemon fireballs
  Hell Knight fireballs
  Baron of Hell fireballs
  Arachnotron plasma
  Revenant missile (homing and non-homing types)
  Mancubus fireballs
  Spider Mastermind bullets
  Cyberdemon rockets (unexploded)
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  Notes: A rocket will not detonate if it touches a ghost;
  but if the rocket detonates against a solid object, any
  ghost within range of the explosion can be affected.
  While Revenant missiles cannot touch a ghost, a homing
  Revenant missile will continue to attempt to strike the
  ghost, unless/until it strikes something else, or the
  ghost is killed by some other force.
  Note that normal-monster weapons will auto-aim as usual
  when used on ghost monsters, but player weapons will not.

7. CAN GHOSTS BE RESURRECTED AGAIN?
===================================
o A killed ghost can be resurrected any number of times by
  an Arch-Vile.  When resurrected, the monster remains in
  ghost form.

o When monster respawning is in effect (through a Respawn
  switch or parameter, or through the built-in respawning
  effect of Nightmare Skill), a killed ghost will respawn
  as a normal monster.

8. WHAT HAPPENED TO THE GHOST I SAW?
====================================
o Ghosts may disappear for a variety of reasons: Sometimes
  a ghost may move out of the level entirely, and wander
  around outside the borders of the map; Walking ghosts can
  become stuck in pits or trenches that normal monsters
  cannot step into; Sometimes ghosts get stuck behind
  objects, or get stuck in parts of structures that they
  cannot move all the way through; When a ghost is killed,
  its corpse may fall into or through a wall, where it
  cannot be seen.

9. WILL A SURVIVING GHOST AFFECT MY SCORE?
==========================================
o In Doom 2: Hell On Earth, any ghost monsters that appear
  have already been killed at least once, and the KILLS
  score in the tally screen will reflect that.  Failing to
  kill a ghost will not subtract points from a KILLS score.

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Copyright 2000.  Updates: http://members.aol.com/ledmeister
