  We develop a new approach that computes approximate equilibrium strategies in
Jotto, a popular word game. Jotto is an extremely large two-player game of
imperfect information; its game tree has many orders of magnitude more states
than games previously studied, including no-limit Texas hold 'em. To address
the fact that the game is so large, we propose a novel strategy representation
called oracular form, in which we do not explicitly represent a strategy, but
rather appeal to an oracle that quickly outputs a sample move from the
strategy's distribution. Our overall approach is based on an extension of the
fictitious play algorithm to this oracular setting. We demonstrate the
superiority of our computed strategies over the strategies computed by a
benchmark algorithm, both in terms of head-to-head and worst-case performance.
