Billiards is a game played between two people on a large cloth-covered table using cues to hit balls into pockets. It originated in the 15th century as a game similar to croquet and evolved to use cue sticks instead of maces. Milestones in billiards included the development of the leather cue tip in the 1830s, use of slate table tops in 1835, and rubber cushions in 1845, which led to its classification as a sport in the 1850s.