flame vs tilt
What you do versus what you suffer. Flame is insulting in chat; tilt is losing your composure after a setback. The first often causes the second.
flame
Flaming is going after a teammate in chat: blame, insults, "diff", "report". It is an act, and it has an author. "stop flaming" is a request aimed at a specific person.
open the page →tilt
Tilt is the state of a player who lost their cool after a death, a failed gank or some flame, and plays worse because of it. It has no author, it happens to you. "im tilted" is an admission, "he is tilted" a diagnosis.
open the page →Why they get mixed up
They follow each other in the same order almost every game: someone flames, someone tilts, and the game falls apart. They blur because both come up at the same moment, but the answer is not the same. To flame, you answer "muted". To tilt, you answer "np we can come back".