• Progressive or Stacking Uno: If a draw card is played, and the next player in turn order has a card with the same symbol, that player can play that card and "stack" the penalty, which adds to the current penalty and passes it to the next player(although a +4 cannot be stacked on a +2, or vice versa).This house rule is so commonly used that there was widespread Twitter surprise in 2019 when Mattel stated that stacking was not part of the standard rules of Uno.
• Seven-O: Every time a "7" is played, whoever played it must swap hands with another player of their choice before ending their turn. Every time a "0" is played, all players pass their hands to the next player in the current direction of play, after which play continues normally.
• Jump-In: If a player has exactly the same card (both number and color) as the top card of the discard pile, they may play it immediately, even if it is not their turn. Play then continues as if that player had just taken their turn.

• Wild Shuffle Hands: The player using this card collects all cards held by all players, then shuffles and re-deals them, starting from the player to their left.
• Wild Customizable: There are three copies of this; these cards are blank and can have a house rule assigned to them.

Each of these cards can be played on any turn and is worth 40 points when a player goes out.