With most information hidden, the game Stratego

What happened

Adding in a second neural network that guesses the identity of hidden pieces was key. Deep Blue took down Garry Kasparov at chess in 1997, AlphaGo beat Lee Sedol at Go in 2016, and poker bots have been beating professionals for years.

But one classic game called Stratego held out. Now, a team of researchers from Carnegie Mellon, MIT, New York University, and Stanford University has done it.

And it took just 16 GPUs (a chip built for many calculations at once, used for graphics and AI) and a few thousand dollars to train it. Hidden armies In Stratego , each player gets 40 pieces representing military ranks, from a marshal down to a spy, plus bombs and a flag.