Some strange things can happen when corporeal creatures attack incorporeal creatures. When incorporeal creatures make full use of their incorporeality, even stranger things can happen.
Attacking Incorporeal Creatures
As noted in Part Three, a corporeal creature has a 50% chance to fail when it attacks an incorporeal creature, and it must use a magic weapon or some kind of magical attack to have any chance to harm the incorporeal creature at all. The failure chance arises from an incorporeal creature's intangible nature -- there's simply no telling if the attack will prove effective. The failure chance applies even to attacks that normally require no attack roll, such as spells and supernatural abilities. For example, a lightning bolt or a dragon's fiery breath both have a 50% chance to fail when aimed at incorporeal creatures. If an attack affects an area that contains multiple incorporeal creatures or otherwise affects multiple incorporeal creatures, check the failure chance separately for each creature. One attack may fail against some incorporeal creatures and succeed against others.
The failure chance doesn't apply to nondamaging effects, such as halt undead spells. A nondamaging effect that creates some kind of physical restraint, such as a web or entangle spell, isn't effective against an incorporeal creature. (Force barriers, such as wall of force, still work, though.) Spells or effects that require corporeal targets or subjects, such as implosion, also don't work against incorporeal creatures.
Normally, miss chances do not stack (a blur spell's 20% miss chance doesn't stack with the 50% miss chance for being completely unseen, for example). In this case, however, you could combine the incorporeal miss chance with a miss chance for attacking a concealed target because one involves uncertainty about exactly where the target is and the other involves an immaterial target that might not vulnerable to the attack at all. To stack the miss chances, check the miss chance for concealment first, then check the incorporeal miss chance; if the attacker fails either miss chance, the attack misses (to save time, you might want to check the highest miss chance first, or just roll both of them at the same time).
As noted in Part Three, some attacks ignore the incorporeal miss chance. The list includes the following:
Force: Anything with the force descriptor has no miss chance against incorporeal subjects. This includes attacks (such as magic missile) and force barriers (such as wall of force).
Positive Energy: Unfortunately, the game has no positive energy descriptor, so you have to study a spell or effect's description to find out if it involves positive energy. The cleric's ability to turn undead creatures is a positive energy effect. The various cure spells also involve positive energy; however, to deliver a cure spell you must touch a creature and your touch is not a positive energy effect. If you're corporeal, your touch attack has a 50% miss chance and if you fail that chance, your touch attack misses and you don't deliver the spell (but you're still holding the charge as noted on page 176 of the Player's Handbook). If you pass the miss chance, you make a melee touch attack against the incorporeal creature and, if you hit, you deliver the spell. The rules don't say so, but you use the same procedure for any other touch range spell. If your touch attack avoids the miss chance, a successful hit delivers the spell to an incorporeal recipient, even if the spell is not a positive energy effect.
Mass versions of cure spells, such as mass cure light wounds, that deliver positive energy over a distance, don't have a miss chance against incorporeal creatures.
Negative Energy: The notes for positive energy apply equally to negative energy.
Ghost Touch Weapons: Weapons with the ghost touch property ignore the incorporeal miss chance.
Incorporeal Attackers: Any attack or effect that an incorporeal creature launches ignores the incorporeal miss chance.
You can splash an incorporeal undead creature with holy water to damage it, but the attack has a 50% miss chance. The Player's Handbook says you must be adjacent to an incorporeal creature to use holy water against it. There's no reason, however, why you couldn't use the rules for splash weapons. Just aim the holy water at a grid intersection near the creature as noted on page 158 of the Player's Handbook. This trick works only if the incorporeal creature is adjacent to the grid intersection you choose and if it is not getting total cover from a corporeal creature or object (see Combat Tactics for Incorporeal Creatures).
An incorporeal creature's lack of a physical body makes certain special attacks moot. For example, a corporeal creature can't bull rush or overrun an incorporeal creature (but it could try to move into its space; see Using Creatures as Cover). A corporeal creature also cannot trip an incorporeal creature.
Armor Classes for Incorporeal Creatures
An incorporeal creature has a base Armor Class of 10, just as any other creature does. The creature's size and Dexterity score also affects an incorporeal creature's Armor Class in the usual way. An incorporeal creature also has a deflection bonus to Armor Class, which is equal to its Charisma modifier, but is always at least +1. This represents the effect that the incorporeal creature's real but nonphysical presence has on the battlefield.
Ghost Touch Armor
Ghost touch armor provides a corporeal creature with its full armor bonus (armor bonus from the armor's kind plus the armor's enhancement bonus) against incorporeal touch attacks (but not regular touch attacks). For example, a dwarf wearing +2 ghost touch half-plate gains the +2 enhancement bonus from the armor and the +7 armor bonus from the half-plate against a spectre's incorporeal touch attack.
When an incorporeal creature wears ghost touch armor, things are little different. Only the armor's enhancement bonus applies to the creature's Armor Class; the basic armor bonus from the armor does not apply. For example, a spectre wearing +2 ghost touch half-plate gains only the +2 enhancement bonus from the armor and does not benefit from the armor +7 armor bonus. The +2 enhancement bonus from the ghost toucharmor is an armor bonus. It applies against incorporeal touch attacks, but not against other kinds of touch attacks (such as rays or touch-range spells).
An incorporeal creature wearing ghost touch armor remains incorporeal and the normal miss chance applies to most attacks made against it. An attack with aghost touch weapon must contend with the ghost touch armor's enhancement bonus, but not with the base armor, as noted above.
An incorporeal creature wearingghost toucharmor isn't actually carrying the armor around -- it just floats along with the creature. The armor is effectively weightless when an incorporeal creature wears it. The armor does not encumber the incorporeal creature, and the armor's Dexterity cap does not apply. The spectre wearing +2 ghost touch half-plate from our previous example has an Armor Class of 17 (+3 Dex, +2 deflection, +2 armor).
If you're uncomfortable with the foregoing text and you would like the ghost touch armor to work pretty much the same way no matter who wears it, you need to figure out how a creature with no physical body and no Strength score wears armor and you also need to figure out its encumbrance. A fairly easy way to handle this is to use the incorporeal creature's Charisma score as its Strength score for purposes of determining the creature's load. The rules say that a creature cannot fly when carrying more than a light load, but you may want to waive that rule for incorporeal creatures (which often have only a flying speed). You also may want to give an incorporeal wearer the full benefit of the base armor's armor bonus and apply the appropriate speed reductions and Dexterity cap for the base armor.
No matter what rules you use for an incorporeal wearer, an incorporeal creature wearing ghost touch armor retains its ability to pass though solid objects and all the special defenses that go along with being incorporeal.
Combat Tactics for Incorporeal Creatures
Even a dull-witted incorporeal creature should know enough to use these combat tricks when fighting corporeal creatures. The notes in this section were drawn in part from the upcoming Libris Mortis tome from Wizards of the Coast.
Staying Mobile: Thanks to their flying speeds and ability to pass through (or at least enter) corporeal objects or creatures, incorporeal creatures enjoy unmatched mobility no matter what conditions prevail on battlefield. In fact, the more cramped or choked with obstacles a battle proves, the greater an incorporeal creature's advantage in mobility over a corporeal foe. An incorporeal creature should move around frequently. When it does so, it should take the shortest available route between two points, which might take it through solid objects. Even when an incorporeal creature cannot move straight through an object because the object is thicker than the creature's face, it usually can cut corners by entering the object briefly.
Using Objects as Cover: An incorporeal creature's ability to pass through (or at least enter) corporeal objects or creatures can prove most exasperating to corporeal foes. In general, an incorporeal creature can claim cover whenever it enters an object that's the same size category that it is or one size category larger. If the incorporeal creature enters an object at least two size categories larger than itself, it has total cover. If, however, the incorporeal creature makes a melee attack outside the larger object's space, it only has cover unless it can retreat back into the object after the attack. For example, if an incorporeal creatures makes a melee attack, then uses a 5-foot step to enter an object at least two sizes bigger than it is, the incorporeal creature has total cover. If the incorporeal creature instead leaves or reaches out of the same object and then attacks, it cannot take a 5-foot step and gains only cover from the object. In either case, the incorporeal creature only has cover while it makes the melee attack.
Using Creatures as Cover: An incorporeal creature can move through corporeal creatures as well as objects. Likewise, a corporeal can move through an incorporeal creature.
When trying to move through a creature, you provoke an attack of opportunity from that creature when you enter its space. To actually enter the other creature's body, you must make a successful touch attack (or incorporeal touch attack) against the other creature. This represents the difficulties involved in actually slipping into the other creature's body. If the attack fails, you must go back to the last space you left. Attempting to move into the other creature's space counts against your movement for the turn, but going back a space does not.
A creature threatens its own space, so you provoke an attack of opportunity when leaving its space.
An incorporeal creature inside a corporeal creature gains cover as noted above. When an incorporeal creature uses a corporeal creature for cover, that cover lasts only so long as the two creatures share the same space. If either the incorporeal creature or the corporeal creature moves away from the shared space, there's no more cover.
When an incorporeal creature is the same size or one size larger than a corporeal creature whose space it shares, the corporeal creature gains concealment. If the incorporeal creature is two or more sizes larger, the corporeal creature has total concealment. However, if the corporeal creature reaches outside the incorporeal creature's space to make a melee attack, it has only concealment unless it can retreat back into the incorporeal creature's space afterward as noted above.
You normally could enter the other creature's space due to a difference in size (see page 149 in the Player's Handbook); no touch attack is required. No touch attack is required to simply move through an ally's space or a helpless creature's space. If you don't make the touch attack and succeed, however, you don't get concealment or cover from the other creature.
Force Effects: A force effect that completely surrounds the user's body, such as the mage armor spell or bracers of armor, prevents an incorporeal creature from occupying the user's space and vice versa, though two creatures' relative sizes might still allow them to share the same space, as noted above.
Incorporeal Combat Miscellany
Remember that incorporeal creatures cannot see through solid objects. When an incorporeal creature claims total cover from an object (or creature), it cannot see anything and is effectively blinded.
An incorporeal creature can make a Listen check to locate corporeal creatures it cannot see (see Part Two). It gains a +2 bonus on Listen checks when inside a solid object.
If you're playing an incorporeal creature in combat against corporeal foes, make sure you don't act on information that the incorporeal creature doesn't have. It's pretty difficult, for example, for an incorporeal creature hiding inside a wall or floor to emerge in exactly the right spot to attack round after round (unless the corporeal foes are foolish enough to stay in one place, or are compelled to do so). In most cases, the incorporeal creature will make a Listen check and determine a corporeal creature's location. After that, the incorporeal creature will have to emerge at least partly from the object where it is hiding to make an attack.
Incorporeal Against Incorporeal
Incorporeal creatures can interact physically with each other -- at least as much as that is possible for creatures that lack physical bodies. They can attack each other without an incorporeal miss chance and they can attempt certain special attacks against each other, as noted here.
Grappling: You can resolve grapple attempts using the rules on pages 155-157 of the Player's Handbook, except that an incorporeal creature uses its Charisma modifier instead of its Strength modifier when it makes a grapple check. Remember that grappling combat begins with an initial grab attempt, not a grapple check. When one incorporeal creature tries to grab another, it makes a melee touch attack and uses its Dexterity modifier for the attack.
Overrun: When one incorporeal creature tries to overrun another, use the attacker's Charisma modifier for the opposed check. The defender can use its Charisma modifier or its Dexterity modifier. Incorporeal creatures can't fall, so it's best to assume that they can't be knocked prone if they fail an opposed check. Instead, just assume that the loser is moved 5 feet in a direction of the winner's choosing; this doesn't count as part of the loser's movement. If a barrier that is impassable to an incorporeal creature prevents movement in the direction the winner chose, it must choose a different direction.
Trip: Although one incorporeal creature can grab another, you can't make an incorporeal creature fall down, even if you're incorporeal yourself.
Next week, we'll move on to examine etherealness.
About the Author
Skip Williams keeps busy with freelance projects for several different game companies and was the Sage of Dragon Magazine for many years. Skip is a co-designer of the D&D 3rd Edition game and the chief architect of the Monster Manual. When not devising swift and cruel deaths for player characters, Skip putters in his kitchen or garden (rabbits and deer are not Skip's friends) or works on repairing and improving the century-old farmhouse that he shares with his wife, Penny, and a growing menagerie of pets.