The Game of Topo

From "The Joy of Mathematics" by Theoni Pappas

Any number of people greater than or equal to 2 can play. There are 3 parts to the game.

  1. building the regions of play
  2. assigning values to some or all of the regions
  3. capturing regions

1. Taking turns, each player draws a region adjacent in some way to a previously drawn region. Ten such regions are drawn by each player.

2. Each player chooses a different colour. Then, taking turns, each player assigns a number value to a region until each player has regions which sum to 100. If a player wants to just assign a region the number 100, then that player would have only 1 region (note: this would not be a very good play). (using the whiteboard program, the text tool with size 3 or so works well.. just remember to click somewhere on the drawing board after you have typed your number, otherwise it won't appear to anyone else)

3. Capturing. A player may capture a region with a number of his/her colour in it if one or more of the adjacent regions belonging to other players total more than that region. Once a region is captured, the player should draw an X or other mark in his/her colour over the number to show that that region has been captured and is out of play. Players take turns capturing as described until no more regions are capturable.

The object of the game: the player who has captured the most regions at the end of the game is the winner. The number value of regions captured is irrelevant.

Step 1: Drawing regions
Step 2: Assignment of number values
Step 3: Capturing (in progress)

Click here to go to the whiteboard. [Password:boo]