TWO-up; the game that is only legal on Anzac Day, bringing veterans and other keen punters together in one heart-racing flip of three coins.

But before you step up to the ring, ask yourself - how well do you really know two-up?

Before 2012, two-up was technically illegal in Queensland, but the boys in blue often turned a blind eye on April 25.

The traditional Australian gambling game was played by diggers to take their minds off the war going on around them and is traditionally played at RSLs.

It involves a designated 'spinner' placing two or three coins tail-up on a skip before tossing them into the air.

The head-side of each coin is polished, while the tail is left dark, so it is clear to everyone in the room if the coin lands heads or tails.

A 'ringie' volunteers to make sure the coins fly at least 10ft into the air.

The ringie can call a 'foul toss' and catch one of the coins if they feel the coins did not fly high enough.

Players gamble on whether the coins will fall with both (obverse) heads up, both (reverse) tails up, or with one coin a head, and one a tail (known as odds).

On Monday, two-up will run from 1pm in Hervey House at the RSL Club.

These games are run by the Hervey Bay Old Salts' Group, with proceeds being donated to charity.