Batnum, a portmanteau of "battle of numbers" is an early BASIC game based on the family of "object pile" games, which includes Nim.
The player and computer take turns removing objects from a pile, with there being a set minimum and maximum amount of objects that can be removed per turn. The objective is to force the computer to take the last object.
The Nimrod was a special purpose computer that played the game of Nim, designed and built by Ferranti and displayed at the Exhibition of Science during the 1951 Festival of Britain.
It was the first digital computer exclusively designed to play a game, though its true intention was to illustrate the principles of the (then novel) digital computer for the public.