Okay, maybe it's 18 if they also both played Clean Slate. Assuming they always toss onto their own card before tossing to their opponents. But that would be only if both players designed their decks specifically to be a total drag. Since Legionoid and Clean Slate both remove themselves from play, they cannot be recycled. Most matches are decided between 6~10 turns (3~5 fights) however. This can be even less with cards that allow additional throws or placement.Like this:Turn 1: Player 1 rollsTurn 2: Player 2 rolls.Turn 3: Player 1 plays Clean Slate, rolls.Turn 4: Player 2 rolls.Turn 5: Player 1 rolls. (Battle, P2 wins)Turn 6: Player 2 rolls.(Battle, P1 wins)Turn 7: Player 1 rolls.Turn 8: Player 2 plays Clean Slate, rollsTurn 9: Player 1 rolls Turn 10: Player 2 rolls (Battle, p1 wins)Turn 11: Player 1 rolls (Battle, P2 wins)Turn 12: Player 2 rollsTurn 13: Player 1 rolls Turn 14: Player 2 rolls (Battle, Legionoid is played)Turn 15: Player 1 rollsTurn 16: Player 2 rolls (Battle, Legionoid is played)Turn 17: Player 1 rollsTurn 18: Player 2 rolls (Battle, victor is decided)Eh, that was kinda hard. And Player 2 could recycle Julie's Throw to make things super-aggravating, but I think I've made my point. This would be the absolute longest a game can be.As for the shortest, it can be done in TWO TURNS!!Turn 1:Player 1 rollsTurn 2: Player 2 rolls, uses moon lance, Player 1 responds with Flames of Light, causing two battles in one turn. Player 1 wins on the card he FoL'd onto and ties on the other. He wins it since he played there first, then plays Balance Echo to place another card into his pile, totalling 3!