The room you would build — turn it, or read the flat plan.
scale hint (never measured): “a table, a floor, anywhere the circle fits”
The pile — beat it or pass
drawn from 2 rules
Leading and beating
playThe player who leads may play any single card, or any set of two, three, or four cards of the same rank. Each player after them, in clockwise order, must either play the same number of cards of a strictly higher rank, or pass. Equal rank does not beat the pile, and you may never change the number of cards mid-pile: a pair lead can only be beaten by a higher pair.
Passing and clearing the pile
playPassing skips only your current turn; you may still play when the turn comes back around to you. When every other player passes in a row after someone's play, the pile is cleared face down and the player who made that last play leads a new pile. If that player has already run out of cards, the lead passes to the next player to their left who still holds cards. Some tables instead lock a passer out until the pile clears — that is a common variant, not this baseline.
click anything else — every element cites the rule it's drawn from.