Tales of Tolgard
Smite, or more commonly known as smite evil, is an ability used most often by paladins to strike a mighty blow. In the case of paladins specifically they are good aligned and strike their mighty blow against a creature that is evil. This attack, often with a sword but works with any weapon, even empty hands, hits with greater accuracy than normal and deals additional damage proportional to the experience of the paladin. This is a concrete expression of the abstract ideal of the wrath of a god so should be used with caution; bringing this destructive, divine energy to bear on an unworthy or innocent opponent may bring complications to the relationship between the paladin and their deity.
There is another side to this ability. A blackguard, or anti-paladin has a similar ability except that it is commonly known as smite good. Other than the source and the target, it functions the same way.