Each person takes a quarter (or any coin).
Gather in a group facing each other.
Flip coins and let land on table or floor.
If all coins match (whether heads or tails), all flip again.
When only one person's coin does not match, that person removes an article of clothing, and the flips continue. (In a group of 4, 3 must have heads or tails, with one person different. With a group of 5, 4 must be the same, and so on. Obviously, the larger the group, the longer the game will last, as odds of only one person being different get greater and greater.)
Continue until one person is completely sans clothing. In groups of 4 or more, the first one nude is out of the game, but he/she can certainly stick around to watch the game continue. Continue the game until the group is down to 3.
If the game started at 3 persons (or when it gets down to 3 players from a start of a larger group), the first one without any clothes continues in the game, but for another purpose.
The 2 remaining people who still have clothing on will flip their coins first. If both flip the same side (both heads or both tails) they flip again. When they each have opposing sides (one has heads and the other tails), then the naked person flips to see who is next to remove an article of clothing. If his/her coin is heads, the person with tails removes something, and vice versa, if naked's is tails, then the person who had heads takes something off.
Continue until only one person has any clothing on.
The person who was last to remove all clothing then flips his/her coin, with the "dressed" person calling heads or tails. If he/she loses the toss, then he/she must finish removing the remainder of his/her clothes. If he/she wins the toss, he/she can either take off his/her remaining clothes, or everyone can get dressed and start over.