I have just started thinking about the logic that might be involved - first timer.
player1 ‘owns’ the game -> has logintoken1, is inserted into collection with _id and token
sends invitation to player2 -> shares login token with player2
player2 accepts -> is inserted into ‘activeplayers’ collection, fields player2_id, login token1
they play = game is unique, game document is linked to login token player1
I could get two players together by sending the _id + loginToken1 of player1 during an invitation to player2, then after accept use the loginToken1 as a requirement to be inserted into an ‘activeplayers’ collection and relate the document for each game to loginTokenn so that every game is unique.
Is that about the way to go ?