How to play mahjong against AI

The mahjong engines on our index have reached the top of Tenhou's ladder. Most of them, you will never sit across from.

That's the gap between mahjong AI research and mahjong AI you can play. Here's how the landscape splits, and where to go when you just want a bot at the table.

The strongest engines are mostly out of reach

Suphx and LuckyJ, the two engines with the best published results, are research systems. You can read the papers and press releases, but you can't open either one and start a game. NAGA reached 10-dan too, and Dwango sells it as a paid review service. You pay to have it analyse your Tenhou games or join a private room, not to play casually.

The open engines, Mortal and Akochan, are real code you can run. But running them means setting up an mjai server, a model and a client. That's a weekend project for a programmer, not a quick game after dinner. And every one of these engines plays only Japanese Riichi.

What players actually want from a bot

When you want a game against AI, you rarely want the strongest possible opponent. You want:

• a game that starts now, with no one waiting on you;
• the rules you actually play at home, not only Riichi;
• a way to look back at a hand and see what you missed.

Where to play: Mahjong Live

Mahjong Live covers all three, free, in the browser. Pick Challenge the AI and you get a table of bot opponents to practise against at your own pace. The site covers Taiwanese, Japanese Riichi, Hong Kong Parlour, Indian and Passport 965 rules, so it's an easy way to learn a new style before playing people.

For Indian mahjong, Analyze steps through a finished game turn by turn, with every hand, discard and claim from all four seats. Seeing what the bots held when they made their discards is the fastest way to start reading a table.

When you're ready for people, the same account takes you to private tables with friends, games against strangers, and tournaments.

If you want to go deeper

If you're a Riichi player who wants an engine to grade your decisions, our engine index lists each engine with what it costs and how to access it. If you're building your own bot, start with the protocols and environments section.