PocketChess is a well-travelled game. Versions have appeared for several handheld or palmtop platforms, including the Palm, Windows CE and, of course, EPOC (the Psion Series 5/5mx/7 and Revo operating system). It's also quite possibly the best, if not the only, free chess game to be fully compatible with the Revo. The EPOC version is produced by PalmTime.

When you start a new game in PocketChess, its three modes become apparant - you can play 'You vs EPOC', 'EPOC vs EPOC' and 'You vs Another Player'. The first is the standard against-the-computer chess game, and comes with eight different difficulty levels - at level 1, the easiest, the computer gets one second to consider its move, but at level 8, the hardest, it gets a massive one minute and fourty-five seconds to calculate! Although I am not a good chess player, I found level 1 pretty difficult to beat, so even talented players should find a challenging level.

'EPOC vs EPOC' is a demo game - you might want to watch the game to improve your own chess playing. 'You vs Another Player' is more interesting, though, as you can play a standard game of chess with it, using PocketChess as the chessboard. After all, a normal chessboard isn't that easy to carry around!

When the game starts, of course, you are tpresented with a standard chess layout, although a 'Board Setup' option allows you to move and remove pieces, to play unusual games or preset layouts. I would quite have liked an option to save and reload layouts, as you must always re-create them each time from scratch. You also cannot re-add removed or taken pieces, but must start all over again.

The default chess pieces are shaded for a 3-D look, although they can be a little difficult to distinguish on the Revo's small screen. Fortunately, an alternate, non-shaded set is available that is a lot clearer.

Moving pieces is simple - you can either drag the pieces or tap once on them and once on their destination. Each move appears in a list to the right of the board, and can be undone. Optional sounds and a symbol in the move list alert you to a check, checkmate or stalemate situation.

If it is check, the game only lets you move pieces in such a way which will remove the check status. This can make averting check a little easy, as you can try every move until you find the right one. I would have preferred an option for turning this off when playing a human opponent, although this isn't a serious problem.

PocketChess also allows all of the standard computer chess options, such as swapping sides, flipping the board and skipping a move. Although games cannot be saved separately, when the application is closed the current game status is stored and then restored the next time you open PocketChess.

Generally, PocketChess is a highly capable portable chess program with many features of commercial versions, and I only have minor gripes with it. Have a go - if you play chess, you may well like it.