A system for playing a game comprises a game unit and a number of mobile terminals which can communicate with the game unit. The game unit is arranged for sending a game code to one or more mobile terminals, and the mobile terminals are arranged for sending at least one game code-related reply message to the game unit. Each reply message comprises an identification code of the mobile terminal. The game code is a number consisting of two or more digits, and each digit identifies a key of each mobile terminal. Each reply message is a word composed of letters which have been selected by means of the keys identified by the digits of the game code. The game unit is arranged for verifying the letters of the reply message.