Needs review
Source: Player's Handbook

Description: You can react more quickly than normal in a fight.

Prerequisites:

Required for: Blackened Sight, Child of Water, Dire Charge, One Leg Stance, Rattlesnake Strike, Reactive Counterspell, Superior Initiative, Victory of the Wind

You get a +4 bonus on initiative checks.

Special

A fighter may select Improved Initiative as one of his fighter bonus feats.