The effects of many feats are hardcoded into the engine. Some were decoupled in NWN:EE and will be noted as such or have ruleset.2da items so the ability can be altered or balanced differently (but not at it's core altered entirely).
Categories of feat:
- Hardcoded Active - Is a hardcoded active ability such as FEAT_KNOCKDOWN. May be tied to a particular class line as well or alter effects if used by a PC or NPC.
- Hardcoded Passive - Has a hardcoded in-game effect such as +1 AC from FEAT_DODGE. May be tied to a particular class line as well or alter effects if used by a PC or NPC.
- Hardcoded Other - Has a hardcoded in-game change but no direct passive bonus as such, and may be referred to specially, such as Metamagic feats.
- Scripted Ability - Linked to a spells.2da entry and thus entirely scripted
- Partially Scripted Ability - Linked to a spells.2da entry but has some hardcoded elements (eg; uses/day of Turn Undead or Bard Song)
- Thematic/Script Only - Does nothing, is there for helping the PC understand their race or class, or only checked for in scripts.