NIM is a game of two players, using tokens in a number of 'heaps'. Each player in turn takes one or more tokens, as they desire, from a single heap. In the 'simple' game, the aim is to take the last token from the last heap. In the 'reverse' version, you try to force the other player to take the last.

Here NIMROD will play you as its opponent. The four rows of lights and buttons in the control panel represent four heaps of up to seven tokens. Before play begins, you should set a desired number of tokens in each heap, by pressing the corresponding buttons. You can also use the switches at the top to pick whether the game is simple or reverse, and whether you or the computer should start. You then switch into PLAY mode and move alternately with the computer until one of you takes (or is forced to take) the last token. Note that when the display indicates "COMPUTER WILL NOW MOVE", it doesn't do so by itself — a press of the "COMP. MOVE" button is needed.

If you need more help in how to operate the panel, try the button at top right of the page. You may find help in how to beat NIMROD by exploring the rest of this site!