Conditional Design

First Step:
The first player draws a line.
The other players draw a line that goes over and under the last drawn line.

In Turns:
The player elongates his/her line on both ends. The elongations have to go over and under a line of another player and may not go over the line of the same color twice in a row.
When a line can no longer be elongated, it is considered dead for the rest of the game. When both ends of a line have died, the player may place a new line.

In de Knoop from Conditional Design on Vimeo.

General:
Every player receives one color sticker sheet.
The growing pattern consists of branches - of which each branch is created with a pair of three polygons - one of each color.

In turns:
Cut a convex quadrilateral (a polygon with four sides) from the sticker sheet
Attach it to an existing quadrilateral.
Attach it so that a pair of three quadrilateras forms together one edge that is as straight as possible.
A branch must not contain more than one quadrilateral of each color.

Convex City Plan from Conditional Design on Vimeo.

http://conditionaldesign.org/