As time passed, increasingly elaborate illegal "two-up schools" grew around Australia, to the consternation of authorities but with the backing of corrupt police. The legendary Thommo's Two-up School, which operated at various locations in Sydney from the early years of the 20th century until at least 1979, was one of Australia's first major illegal gambling operations. The popularity of Two-up declined after the 1950s as more sophisticated forms of gambling like Baccarat gained popularity in illegal gaming houses and poker machines (slot machines) were legalised in clubs.
Legal Two-up arrived with its introduction as a "table" game at the new casino in Hobart in 1973 and is still offered in some Australian casinos. Two-up has also been legalised* on ANZAC Day, when it is played in Returned Servicemen's Leagues (RSL) clubs and hotels. Several tourist "Two-up schools" in the Outback have also been legalised. According to the NSW Gambling (Two-Up) Act 1998, two-up in NSW is not unlawful on ANZAC day.
| Term | Meaning |
|---|---|
| Spinner | The person who throws the coins up in the air. Each person in the group takes turns at being the spinner. |
| Boxer | Person who manages the game and the betting, and doesn't participate in betting. |
| Ringkeeper (Ringy) | Person who looks after the coins after each toss (to avoid loss or interference). |
| Kip | A small piece of wood on which the coins are placed before being tossed. One coin is placed heads up, the other tails up. |
| Heads | Both coins land with the 'head' side facing up. (Probability 25%) (see also) |
| Tails | Both coins land with the 'tails' side facing up. (Probability 25%) (see also) |
| Odds | One coin lands with the 'head' side up, and the other lands with the 'tails' side up. (Probability 50%) (see also) |
A person is selected as the Spinner (generally greeted to loud calls of "Come in Spinner!" by the rest of the players). The Spinner will be tossing the coins in the air using the kip until they win or lose.
The basic format of the game:
The Spinner is required to place a bet before their first throw that must be covered (equalled) by another player. If the Spinner wins they keep the bet and cover, otherwise it goes to the player who covered the bet. The Boxer takes a commission out of this bet.
The other members of the group place side bets (bets against each other) on whether the Spinner will win or lose and the result of the next throw.
Variations revolve around the definition of "win" and "lose" for the Spinner. Some variations include:
When played in casinos the Spinner's bet is covered by the house, as are the side-bets by the group of punters.

In 1978, the Australian group the Little River Band released "Sleeper Catcher", their fourth album. In the liner notes it says:
The movie The Sundowners contains a sequence in which several Australian drovers (one of them portrayed by Robert Mitchum) play a game of two-up, with appropriate bets. One of the players calls out "Fair Go", which translates roughly as "Play fair". Appropriately, the action in the game on-screen is rapid and without hesitations or false starts, but this makes it more difficult for the audience to determine the rules.
A similar sequence can be found in the 1971 film Wake in Fright.
The book Come In Spinner takes its name from the call.