You score the game (on a nice large chalkboard or 2)

The gist of the game is you throw your 3 darts (leave them in the board while you chalk your score) and you score on all 3 of the games with those 3 darts. For instance you throw at the double 20 but hit 2 single 20s and a single 5. So would would score nothing on the 301 (you missed the double), but on the 501 you would minus 45 (20+20+5) leaving you 456 (in 501) then score your cricket 2x20's.

Strategy: You don't have to start at 20's but just like cricket, 20 is the strongest number. Aiming at doubles first is one way to go.
When I played chaos for the first time, I missed my double 20 with all 3 darts and on my second turn threw at my double, double 16 and got in, but since my opponent had closed 20 and 19 in cricket, I finished off the 16's and went to 17's.

On the the other hand, one could write off 301 and just concentrate on a good cricket / 501 game. Remember you only need win 2 out the the three games to be the winner!

Once you play this game, you'll want to play again and again.