Coordinate Connect

This is a modification of a game that I can not remember where I saw. EDIT:  Yeah, remembered!  It was at NRICH, the game of the month.  They have a java implementation.  Give it a go.

Modifications by Jill, Leah, Lauren, Ashley, Megan, Nick, Jenn, Alyssa (Preservice geometry K-8 class) and myself.

Game:  Coordinate Connection

Materials:  10x10 grid with no axes, pen (or colored writing utensils)

Gameplay:  The idea of the game is players take turns naming a coordinate pair and then filling in the point.  The first player to make four in a row, wins.

The first point of the first player is the origin, (0,0).  It still counts as their point and can be one of the four in a row.  Later points are given by naming a coordinate pair.  For example, (2,-3), is two to the right of the origin and 3 below it.

Players take turns naming a point and then marking it.  If it's not where you thought, too bad, so sad, that's where it goes.  (Unless another point is already there - lucky.)  If players are having a tough time just verbalizing it, they can be required to write the coordinates down before drawing the point.

The winner is the first player to get four in a row, vertically, horizontally or diagonally.  The loser decides whether they want to go first or second in the next game.

Hints:

• consider blocking your opponent from getting three in a row. 
• get and stay on the offensive
• use a special mark

Variations:

• Play with three or four people.  (This was surprisingly fun and complex.)
• Allow any 4 consecutive collinear points to win.  For example, (-3,-3), (-2,-1),(-1,1), and (0,3)
• Play with younger students by giving directions from home, such as 2 left and 3 up.
• In the original game, you marked the point then said the coordinates, losing it if you were incorrect.

Give it a go, and let us know what you think!

Paper for playing - 2 sided, 4 10x10 grids each side.

Sample game: