1. Ender's Game - $28 million
2. Jackass Presents: Bad Grandpa - $20.5 million
3. Last Vegas - $16.5 million
4. Free Birds - $16.2 million
5. Gravity - $13.1 million

As expected, Ender's Game topped the box office, earning $28 million in its debut weekend.

Bad Grandpa slipped from first to second with $20.5 million.

Last Vegas -- starring Robert De NiroMorgan Freeman and Michael Douglas -- opened in third with $16.5 million, just ahead of another new flick, the animated Free Birds, which earned $16.2 million.

Gravity dropped from second to fifth with $13.1 million.