RPG stands for Role Playing Game.
It comes directly from pen and paper Roleplaying games such as the classical Dungeons and Dragons or the British Warhammer Fantasy Roleplay (from Games Workshop's famous franchise)
It often includes Wargames mechanics, with a strong Fluff wise story telling.
This genre was sadly rarely ported on Amstrad CPC...as Adventures games were far more common.
Contents of a proper RPG
A proper RPG shall inlude some kind GUI.
And an evolution system for Player's characters.