The ‘On fire’ idea of having a new rule for the "11s" cards has inspired my group to make a deck of cards that come into effect as soon as player plays one of the 11s. We call them the Nightmare cards. One is dealt face up at the start of the game and will take effect as soon as one of the 11s is played. Then the next Nightmare card is shown, and that will come into effect when the next of the 11s is played.
Nightmare cards only apply for that turn, unless otherwise stated.
Please feel free to suggest more ideas.
Here are the cards we use.
Play now goes in reverse order. This stays in effect until the next Nightmare card is played
You must play three cards this turn, including this one, even if the draw deck is empty
You can only play this one card
The next player can only play one card
The next player cannot play on this pile
This card can only be covered with a card at least 10 away
This card can only be covered with a card in the same decade [eg if 55 played, then must be covered by a number from 50 to 59, in the ‘right’ direction of course]
This must be the first card you play
This must be the second card you play
All players rotate hands anticlockwise immediately
All players choose a card from their hand, shuffle it back into the draw deck and take another
Choose a pile – it now starts going in the reverse direction. This stays in effect for the rest of the game
‘Perfecto’ is now 20 away, not 10. [‘Perfecto’ is our name for going in the ‘wrong’ direction’.]