Can a Ghost use feats that have a strength score as a prerequisite?

Question

A Ghost has a strength score, but it can only use physical force as long as it is on the ethereal plane. When a Ghost uses its manifestation ability, "it partly enters the Material Plane and becomes visible but incorporeal on the Material Plane."

As an incorporeal creature it uses its dex modifier on attack rolls instead of its strength modifier, because, like other incorporeal creatures (Spectres, Wraiths, etc), a manifested Ghost has no strength score (or cannot make use of it) when dealing with corporeal creatures.

What does this mean regarding feats that have a strength score as a prerequisite like power attack or cleave? Can a manifested Ghost still use them?

– And (by the way): is there any way (by feats ore magic items), a manifested Ghost can make use of its strength on attack and damage?

---

Background: I am currently preparing a little scenario with a knight who turned into a ghost long ago but still dutifully defends his castle. I do not want to him to moan, make touch attacks or gaze but rather fight like the old style chevalier he used to be (and still thinks, he is). I equipped him with a ghost touch weapon, so that his attacks vs corporeal creatures do not have a chance to fail. But, seemingly, becoming a Ghost has some disadvantages for someone who used to rely on strength a lot ...

Answer 1

In General

A creature that no longer meets the pre-requisites of a feat can no longer use that feat.

While manifested a ghost has a strength of -. Feats, prestige class abilities, some magic items etc that have a prerequisite of 'strength X' will not function for that ghost while it has a strength score of -. While not 'manifested' a ghost has a strength score as normal but exists on the ethereal plane not the material one.

In Specific

In this case, the GM should rule that this Ghost has an ability or special rule that allows him to continue to use his combat feats while manifested due to his special nature as a chevalier who doesn't realize he is dead. Further he should be able to strike at foes with his sword and even wear armour.

In that scenario he's a special monster or npc with modified stats to reflect his fluff, which is perfectly permissible under the basic rules of DnD 3.5e (the DM is the final arbiter of all rules and can modify monster stats to reflect any situation where the monster is different than the norm or otherwise has different abilities).

As a general rule of thumb, changes to monsters should be specific in order to maintain consistency in their application (a specific rule or specific numeric change) but changing monsters 'on the fly' to reflect altered circumstances or in response to story cues (unexpected actions by players) is perfectly justified and common practice.

More specifically, you may modify this ghost so it has a special rule that its Charisma score counts as its Strength score for all purposes while manifested and that it can touch and manipulate objects with its incorporeal body via a telekinesis-like effect (a Su ability). That would allow it to use combat feats that require Strength, allow it to engage in melee combat, and wear worn armour. You may wish to rule that given this 'solidity' it loses some traits of the Incorporeal subtype such as being able to pass through objects and/or (depending on your party's abilities and general attack bonii) its ability to add its Charisma modifier to its AC as a deflection bonus. Likewise you would almost certainly rule that sword it is wielding does not bypass worn armour and would be a regular rather than Touch attack.

If during the encounter your players reason that it being able to touch things mean they should be able to hold it down so the Bard can show it the diary of the lady the chevalier loved in life so he can realize he is dead and find rest, you might rule that it can also be grappled (despite not having added that to the initial rule you formed for this monster). Making logical extensions to rules you did not initially modify adds to consistency - and should generally be the case any time you modify the rules.

Answer 2

Yes, a ghost can take these feats, assuming its Strength is high enough, because a ghost has a Strength score.

Abilities

Same as the base creature, except that the ghost has no Constitution score, and its Charisma score increases by +4.

^{(Ghost Template Description)}

Nothing here says that the ghost loses its Strength score. They lose any Constitution score, but not Strength. The ghost’s Strength is “Same as the base creature.”

Moreover, the ghost even uses its Strength score:

Corrupting Touch (Su)

A ghost that hits a living target with its incorporeal touch attack deals 1d6 points of damage. Against ethereal opponents, it adds its Strength modifier to attack and damage rolls. Against nonethereal opponents, it adds its Dexterity modifier to attack rolls only.

Draining Touch (Su)

A ghost that hits a living target with its incorporeal touch attack drains 1d4 points from any one ability score it selects. On each such successful attack, the ghost heals 5 points of damage to itself. Against ethereal opponents, it adds its Strength modifier to attack rolls only. Against nonethereal opponents, it adds its Dexterity modifier to attack rolls only.

^{(Ghost Template Description, emphasis mine)}

These explicitly indicate that a ghost has a Strength modifier to use. They don’t get to use it against non-ethereal opponents, but it still exists, and that’s good enough for Power Attack and other feats.

While manifested, the ghost does lose their Strength score—but this is just temporary. In theory, one could argue that if the ghost “leveled up” while manifested, they wouldn’t have the Strength score necessary to take the feat, but since it is not their default state, and ghosts are almost-always NPCs that don’t level-up anyway, this can be ignored.

Beyond that, the game supports meeting prerequisites with temporary effects. The game isn’t really clear about how exactly that works—it’s a concept that’s alluded to but never really explained—but the general consensus is that it’s fine to allow characters to meet feat prerequisites with temporary effects—after all, the game covers what to do if feat prerequisites are lost, you just can’t use the feat. So if you meet a feat’s requirements temporarily and then no longer meet them, you just can’t use the feat. Most DMs will allow this kind of thing even if the source of temporary access to a prerequisite isn’t necessarily active at the moment of leveling up (for feats; prestige classes are a different story because once you take 1st level, prerequisites no longer matter, which can make temporarily meeting the requirements rather cheesy and something DMs may want to stop).

Answer 3

Yes, there are multiple ways.

As other answers have already adequately addressed the fact that ghosts still have a strength score, and can still apply it, I shall focus on how to apply a ghost's STR mod to physical objects when manifested specifically.

---

The rather unpopular Ghostwalk Campaign Option has various methods for a ghost to be able to interact with physical objects and individuals, even without using the entire optional ruleset. There are some spells, and some magic items... but my personal preference is a feat which allows a ghost to generate ghost touch ectoplasm (1 lb per standard action) which can be smeared on their body to various effects. It takes 10 lbs of ectoplasm to cover a medium creature. Once covered in Ectoplasm, their entire body is enhanced by the ghost touch effect, and then the ghost can interact normally, including STR effects, against material targets. Optionally, they can just cover their hands if they choose.

The feat Ectoplasm [Ghost][Shaper], can be found on p30.

While the rule set is not the favorite of most, due to presenting a completely separate set of campaign setting flavors and spins on the afterlife (even harkening back to 1e mechanics in at least one aspect) when compared to standard (Greyhawk) D&D or any of the other D&D campaign settings available... the options have their occasional uses, especially when adding flavor to ghosts.