Change your preferences here.
When the wielder scores a critical hit, the critical hit deals 3x damage rather than 2x damage.
Sniper really isn't that good of an ability if you consider that critical hits only have a 6.25% chance of happening. The best Pokemon to use it with might be Drapion since it can use Night Slash, but really Drapion has no place in OU currently. Kingdra gets it also, but it also gets Swift Swim, a much better ability, so it is very rare you will see Sniper come into effect.
Found in Dream World