Twelve starts off with sixteen dice, 1 1 1, 2 2 2,  3 3 3 3,  4 4 4, 5 5 5. These pieces are randomly divided between two players.

Players take turns putting one of their unused pieces on an empty position on the board. Each time a player makes a vertical or horizontal row of exactly twelve, the player scores a point.

3, 3, 4, 2 would get a point
5, 4, empty, 3 would get a point

Pennies are used to keep score. The player with the most points wins.
 
 

After some debate about using posterboard with holes in it, coloured popsicle sticks were used to make the board. The goal was to mark positions in a way that preserved the nice blueness of the board. Get a white coloured pencil and a ruler - but do not use tape to mark edges. Ordinary (dollar store) dice were used as pieces, but all those numbers were confusing. Pips can be nicely, permanently removed by scraping them out, but that takes forever. A drill was much faster, but that distorts the dice. The successful solution was using off-brand liquid paper from the dollar store.
 
 
 
 

The board for Twelve was nicely, successfully made. But the pieces are a problem. The plan was to use ordinary dice as pieces, convenient and easy to manipulate. However, the multiple numbers on a die are dazzling, confusing. There were attempts to make most of the faces white, but this is not straightforward.

Back to considering posterboard. Deep blue posterboard blue corrugated posterboard, which would contrast with the white dice. Layers of posterboard, with square holes so that a die can sit in a recess. The possible advantage of this is the sides of the die would not be so visible. Another advantage is that small square recesses will keep things in line.