Fanorona

It is a board game from Madagascar that was popular amongst sailors.

Play it locally with a friend or against the computer enemy.

Rules

The goal is to remove all of opponent's stones. You can capture one by moving one of your own stones towards or away from an opponent's stone. 

You can move a stone one field along the lines. If a capturing move is possible, it is obligatory. 

It is possible to chain capture moves. But then you may not touch the same field twice and your piece has to change its direction. 

To learn it, it is propably the best to start with the 3x3 version, available via the settings. The game always shows you what moves are currently possible, so I hope it is easy enough to understand the rules by playing!