Sim is a very simple paper and pencil game for two players.

Mark six dots on a piece of paper in a regular hexagon. Each player chooses a different colour pen to use. They take it in turns to draw a line from one point to any other. The loser is the first person to complete a triangle with all sides drawn in their colour.

In general, it is best to complete triangles with two sides in your colour rather than one, as this reduces the options for your opponent.