Historical Rules · 1 May 2011
Rule 705.1
Official source text from the 1 May 2011 Rules release
To flip a coin for an object that cares whether a player wins or loses the flip, the affected player flips the coin and calls "heads" or "tails." If the call matches the result, that player wins the flip. Otherwise, the player loses the flip. Only the player who flips the coin wins or loses the flip; no other players are involved.