Draconic Archivist
( Heroes of Horror, p. 122)In addition to your studies of the darkness, you have spent time studying dragons and constructs.|||As an immediate action (see page 122), you can give up an arcane spell slot to gain a bonus on all saving throws until the start of your next turn. The bonus equals the level of the spell slot used. You can declare that you are using this ability after you have rolled a save, but you must do so before the DM reveals whether the saving throw succeeded or failed.
Prerequisite
Dark knowledge,
Benefit
You can use your dark knowledge ability on dragons and constructs. You use Knowledge (arcana) for dark knowledge checks regarding these two creature types.
Normal
Without this feat, a character with dark knowledge can use that class feature only on aberrations, elementals, magical beasts, outsiders, and undead.