Halfling Luck 
Feat 1
Source Pathfinder Core Rulebook
Frequency once per day
Trigger You fail a skill check or saving throw.
Your happy-go-lucky nature makes it seem like misfortune avoids you, and to an extent, that might even be true. You can reroll the triggering check, but you must use the new result, even if it's worse than your first roll.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
FortuneA fortune effect beneficially alters how you roll your dice. You can never have more than one fortune effect alter a single roll. If multiple fortune effects would apply, you have to pick which to use. If a fortune effect and a misfortune effect would apply to the same roll, the two cancel each other out, and you roll normally.
HalflingA creature with this trait is a member of the halfling ancestry. These small people are friendly wanderers considered to be lucky. An ability with this trait can be used or selected only by halflings. A weapon with this trait is created and used by halflings.