If a mistake is made in a Pokemon game, and neither player catches it, does the player who failed to do the correct action lose the game, or is the game a draw, or do you continue to play the game since the mistake was overlook. Example: A coin was suppose to be toss and if tails the Pokemon could not attack. I failed to (overlook) the toss, several turns later I realize my mistake. This mistake may have put me ahead in the game (if the toss had been tails.) I forfeited the game and later try to look up an official rule on this to no avail.
It depends whether it is casual or tournament play, and if tournament, if it is lower or higher ranked one and if the players are young or teen/adult.
In casual play, both players have to agree on the resolution of the game state, i.e.
- ignore the mistake
- try to rewind the game state to the point before the mistake
- the opposing player draws a Prize card (or more of them)
- player who made the mistake loses
In tournaments, everything depends on the official Judge - he/she is the only one who can rule the resolution of the game state. In addition to previous resolutions, he/she can give a Caution or a Warning to one or both players.
If I was the Judge overseeing tournament where this game happened, my resolution would be:
- player who made the mistake: Prize Card penalty or Multi Prize Card penalty depending on the particular attack and game state (the opposing player draws Prize card(s) for free)
- opposing player: Caution or Warning for not maintaining proper game state (even the opposing player have to watch the play)
But it really strongly depends on the particular Game state.
According to the Play! Pokemon Penalty Guidelines it depends on the severity of the mistake made, and the Tier in which you are playing. It can range from a Caution all the way up to a Game Loss.
For you example it would probably be a Game-Play Error - Major for "Using an Ability when a card prevents its use". For this error in a Tier 1 match you would get a Warning, in a Tier 2 your opponent would get to pick a Prize Card. In either case your opponent would get a Caution for failing to maintain game state.