About

DoubleFives is All-Fives dominoes — the scoring variant, where every play that makes the open ends sum to a multiple of five scores that sum, and the hand ends when someone runs out or nobody can go. Standard rules by default, with RaceHorse and other variants, at two, three or four seats.

The opponent is the point. It is a policy network trained by self-play through twenty-two generations, and it does not cheat: it sees exactly what you see, has no knowledge of your hand, and plays from the same board. When it beats you it is because it counted better, and Coach Mode will show you the count it made.

It is a game of arithmetic under partial information, which is a nicer way of saying you will lose several times before you notice what you have been doing wrong. The ELO rating exists so that noticing is measurable rather than a feeling.

How it pays for itself

Advertising on the free tier — on menus, between hands and on end screens, never during a live hand — with a one-time ad-free unlock to come. That is the whole business model for this game. Which analytics and advertising vendors we let near you is listed by name in the Privacy Policy; if a tool sets a cookie, it is in there.

Who makes it

DoubleFives is made by Screwcap Games, LLC, a small independent studio in Walworth County, Wisconsin. We build games about judgment under uncertainty — monetary policy, commodity markets, household finance — and a few card and domino games that are just games. The rest of the catalogue is at Screwcap.Games.

Bugs, corrections, licensing, or an argument about the rules: play@screwcapholdings.com. Corrections to the data or the history get answered first — if something here is factually wrong, we want to know before a player does.