Coherent in Games

Coherent means logical or rational. It means you are thinking clearly and understand what is being said. So if your creating a coherent world or story you are showing and telling the story clearly and the audience or player understands and feels more connected to the game. This is good as its been shown clearly and the player knows where he stands as the character. A good story and game world is successful depending on how well its made, To create a good coherent world it depends on many things like a good game world design, characters, music, sound effects, story, history, linear or non-linear and game-play. 

If I had to name a game i was drawn in by through its story and coherent world it would be Final Fantasy 10 as its very clear and the characters are well designed and fits in well with the game world which is important for an example if batman was in Spira (Final Fantasy 10 game world) it would break the realism of the game and the player would not be connected and drawn into the game.