Hashi
Hashi uses the concept behind the Hashiwokakero logic puzzles (a.k.a. Hashi or Bridges) of connecting islands with bridges, but is a competitive game in which you try to "complete" as many islands as possible.
To set up, all players decide on which side of the board to use; each side shows 18 islands: 4 with a red flag and 3 with a blue flag, with all others having no flags. Write a 3 or 4 on a non-flagged island, then give this board to the player on your left. Remove one of the 18 number cards from the shuffled deck without revealing it.
