Hi, When i want to use the method chat1.combattre(chat2) for instance, when i validate the exercice i have an error like "method combattre mustn't read data from keyboard". very weird. So i tried with a simple "if" condition which apparently doesn't meet the exercice requirements. I want to use "this" but i have still a little lack of comprehension about..this ^^. And i see that i have to use chat1combattre(chat2) and chat2.combattre(chat1). Or do I do what I want ? sometimes statements are not clear.