Valid Moves

The diagram below shows the valid moves to make, from any given point in a turn.

The grey bubbles are conditions – things that must be true in order for that move to be valid.

Arrows without a grey buble are always a valid move.

A few specific cases:

If I’ve played a CONTINUE, do I have to play another card?

No. After playing a CONTINUE you can choose to move to “end turn” (as there’s a line from “play card” to “end turn”). You can also choose to play another card, if you played a continue.

Is it valid to SAY_UNO / SAY_DUO / SAY_TRIO if you don’t have 1/2/3 cards in your hand, and you’re not calling somebody out?

No. There’s no way in the diagram to get to those states other than through the moves specified above.

When does it become the next player’s turn?

Only after a player makes a move with the END_TURN action. There is no action that will automatically end the player’s turn.

Is it valid to make any moves after the game has ended?

No.

Is it valid to call the previous player out if you’re wrong?

Yes. It’s a valid move to call somebody out at the start of your turn. If you’re wrong (i.e. if they did SAY_UNO, or didn’t need to SAY_UNO), then you get a penalty, but it’s still a valid move.

It’s a valid move to SAY_UNO (or DUO or TRIO) in the move immediately after you’ve played a card, that’s left you with 1/2/3 cards in your hand. You don’t have to say it then, but if you don’t, the next player could call you out on it and you would be penalised.

It’s an invalid move to say UNO/DUO/TRIO at any other point during the game.