Lucky Punch

Ups critical hit ratio of Chansey.

Lucky Punch is a Chansey-exclusive item that dramatically increases its critical hit rate. Combined with high-crit moves, Chansey can land crits frequently!

Honestly, Chansey here is almost never used offensively since its Attack is terrible and you can just get a Blissey. Chansey with Eviolite is a much more common build. Lucky Punch is mostly a novelty item but if you're looking for crits specifically then here you go!