A bonus to an ability score or skill resulting from powerful magic, such as a wish. Inherent bonuses cannot be dispelled. A character is limited to a total inherent bonus of +5 to any ability score. Multiple inherent bonuses to a particular ability score do not stack, so only the best one applies. All inherent bonuses to ability scores result from reading ability tomes (or consuming a Birthday Cake of Wishes, an anniversary reward given to players in 2008). Inherent bonuses to ability score are kept with any form of reincarnation. They apply gradually as you level up (+1 at 3rd level, +2 at 7th, +3 at 11th, +4 at 15th and +5 at 19th).
Inherent bonuses on equippable items no longer exist as of Update 14.