Source: Player's Handbook
You understand how to use all types of simple weapons in combat (see Weapons, for a list of simple. weapons).
Benefit: You make attack rolls with simple weapons normally.
Special: All characters except for druids, monks, rogues, and wizards are automatically proficient with all simple weapons. They do not need to select this feat.
A wizard who casts the spell Tenser's transformation on herself gains proficiency with all simple weapons for the duration of the spell.
Normal: When using a weapon with which you are not proficient, you take a -4 penalty on attack rolls.