This is a game of the Rams group which was popular in England from the 17th to the 19th century. It is played by 3 to 8 players, using a 52 card pack. There are versions in which three or five cards are dealt. In either case players have the opportunity to stay in or drop out. Anyone who stays in takes a proportionate share of the pot for each trick they take, but has to pay in an amount equal to the whole pot if they fail to take any tricks. In some versions players who decide to play have the chance to discard some of their cards and have their hand replenished from the undealt stock.
Rules for Three card and Five Card Loo can be found on David Parlett's Loo page.