How to play
Two-Up is the Australian coin game best known from Anzac Day, when it’s traditionally played in pubs and clubs. A spinner throws two pennies off a flat paddle, and the crowd bets on how they come down. Here you’re the only punter at the ring, and the house holds the bank.
- Choose a chip: 100, 500, 1,000 or 5,000 credits.
- Tap Heads, Tails or both to put chips down. Each side takes up to 10,000 credits, in steps of 100.
- Press Spin. The message reads “Come in, spinner!” and the coins go up.
Each toss lands one of three ways:
- Two heads. Heads wins, paid 1 to 1. The round ends.
- Two tails. Tails wins, paid 1 to 1. The round ends.
- One of each. That’s called “odds”. Nothing is decided, and the coins go up again.
There’s one catch. If odds comes up five times in a row, the spin has “odded out” and every bet on the ring loses, Heads and Tails alike. The five dots under the coins fill in as odds are thrown, so you can watch the count climb, and the line beneath them reports each toss.
Clear takes your chips back, Rebet puts last round’s bets down again, and the strip of recent results shows Heads, Tails and Odded out for the last 20 rounds. If you run out, you can top up with 10,000 free credits.
How a round plays out
Every toss is half “odds” and half a decision, split evenly between heads and tails. So the round usually ends quickly:
| Ends on | Chance |
|---|---|
| Toss 1 | 50% |
| Toss 2 | 25% |
| Toss 3 | 12.5% |
| Toss 4 | 6.25% |
| Toss 5 (decided) | 3.125% |
| Odded out | 3.125% (1 in 32) |
On average a round takes just under two tosses. The odd-out only exists on the fifth throw: once four odds are already on the board, that next toss is a straight 50% chance of losing everything on the ring.
The house edge
Take away the 1-in-32 odd-out and Heads and Tails each win 31 rounds in 64. An even-money bet that wins 31 times in 64 has a house edge of exactly 1/32, which is 3.125%. The long-run return on either side is 96.875%.
That single house rule is the entire edge. Without it, Two-Up would be a pure coin flip with no advantage for anyone, which is why casino versions add it.
Strategy
The coins don’t remember anything. A run of five Heads results doesn’t make Tails more likely, and neither does a recent odd-out. The two sides are perfectly symmetric, so which one you back is a matter of taste.
A few things are still worth knowing:
- Backing both sides doesn’t hedge the house rule. On a normal decision, one side wins what the other loses, so you break even. On an odd-out, both lose. Your loss rate stays 3.125% of everything you stake.
- Bigger bets don’t improve the odds. They only make the 1-in-32 odd-out hurt more when it arrives.
- Expect an odd-out now and then. At 1 in 32, you’ll see roughly three in a hundred rounds, sometimes back to back, sometimes none for a long stretch.
For other even-money guessing games, Coin Flip is a single coin, and Chō-han does the same thing with two dice and odd or even.
If you enjoy Two-Up, try Under Over Seven or Video Poker (Jacks or Better) next.
