Skill Focus

(Player's Handbook v.3.5, page 100, DnD 3.5)

[General]

Choose a skill, such as Move Silently. You have a special knack with that skill.

Benefit

You get a +3 bonus on all checks involving that skill.

Special

You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new skill.