Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3371611.

The stock game comes with only one short ruler! With this, you can print off one for each player.

The ruler is a little longer than the stock ruler at 12 units long (up from 10) and features raised indicators on the commonly-used multiples of three. Because it's symmetrical, it can be used either direction, and the straight side can be used as a ruler.