Bardic Knowledge

Bard Class Ability (1st Level)

A bard may make a special bardic knowledge check with a bonus equal to his bard level + his Intelligence modifier to see whether he knows some relevant information about local notable people, legendary items, or noteworthy places. (If the bard has 5 or more ranks in Knowledge (history), he gains a +2 bonus on this check.)

A successful bardic knowledge check will not reveal the powers of a magic item but may give a hint as to its general function. A bard may not take 10 or take 20 on this check; this sort of knowledge is essentially random.

DC	Type of Knowledge
10	Common, known by at least a substantial minority drinking; common legends of the local population.
20	Uncommon but available, known by only a few people legends.
25	Obscure, known by few, hard to come by.
30	Extremely obscure, known by very few, possibly forgotten by most who once knew it, possibly known only by those who don't understand the significance of the knowledge.

Source: Player's Handbook