Standard 52-card deck, Ace high. 2 to 4 players: any mix of people (pass-and-play on one device) and computer players.
Deal: everyone gets 3 face-down cards and 6 cards in hand, then chooses 3 of the 6 to lay face up on the face-down cards. The other 3 stay in hand.
Order: play from your hand, then your face-up cards, then your face-down cards. Face-down cards are played blind; if one can't beat the pile, you pick up the pile plus that card.
Play a card equal to or higher than the pile. While the draw pile lasts, draw back up to 3 in hand.
Doubles/triples: two or three cards of the same rank can be played together; the group must still beat the pile.
If you can't play, you pick up the pile (then play again).
2 resets the pile: goes on anything, and you play the next card.
7 is see-through: goes on anything, never skips anyone and never gives you another turn. The next player must beat the card under the 7 (King under it means King or higher).
10 burns the whole pile and you go again.
Four of a kind on the pile burns it and you go again.
You may finish on a 2, 7 or 10. First player out wins.
Who starts: lowest ordinary card in hand (3♣ lowest). Stalemate (app rule): if the exact same position comes round four times, it's a draw.