This is an original Poker (Pagat link) variant with 2-cards hands. It's inspired by a 2-card poker variant that I can't seem to find again.
It was mostly made to calculate a bunch of probability and trying to make a bot for it (it didn't work out). Never played it against a human (and not really against the machine for that matter).
You need one french-suited (aka "standard") 52 cards deck (no jokers) and 2 to 17 players. I'm not recommending 17 players it's simply the physical maximum with a 52 cards deck.
As in poker, the goal is to win chips from other players by having a better hand and tactically betting, raising, and folding.
Cards are ranked 2-3-4-5-6-7-8-9-10-J-Q-K-A. For some combinations the Ace might be considered low, but for tiebreaker purposes it is almost always high.
Initial deal of chips, blinds, and how betting rounds function are all identical to Poker. I am not confident in explaining them, but there's detailled page on Pagat that explains it.
Each player is dealt a hand of 2 cards. Then, each player chooses one of their two cards to turn face up, making it visible to all players.
After the deal, a betting round starts. If all but one player fold, then that player wins the hand.
If the betting round ends with more than one player, then one more card is dealt to each player still up and the second and last betting round starts.
If the second betting round ends with more than one player, then each player still up reveals their hand. The one with the best hand wins the pot.
Once the hand is over, any player out of chips loses, and the remaining players deal another hand to continue.
Hands are made using 2 of the 3 cards the players have been dealt.
Hands with the same combination are tiebroken with the ranks of the cards making them (see each hand for how that is done).
If the hands are still a tie, then the last tiebreaker is the rank of the 3rd card.
Any hand in this table beats all hands below it. Suits aren't specified in the example since it's induced by the combination.
| Hand | Content | Example | Tiebreaker |
|---|---|---|---|
| 7 & 8 Flush | A 7 and a 8 of the same suit. | 7 8 | None. |
| 7 & 8 | A 7 and a 8 of different suits. | 7 8 | None. |
| 15 Flush | Two cards of the same suit whose numbers sum to exactly 15 (face cards count as 10). | 5 J | Highest card of the hand, 6 9 is the weakest and 5 K the strongest. |
| Straight Flush | Two consecutive cards of the same suit. | 5 6 | Highest card of the hand, A 2 is the weakest and K A the strongest. |
| 15 | Two cards of different suits whose numbers sum to exactly 15 (face cards count as 10). | 5 Q | Highest card of the hand, 6 9 is the weakest and 5 K the strongest. |
| Pair | Two cards of the same rank. | 9 9 | Rank of the pair, 2 is the weakest and A the strongest. |
| Straight | Two consecutive cards of different suits. | 3 4 | Highest card of the hand, A 2 is the weakest and K A the strongest. |
| Flush | Two cards of the same suit that don't form any other hand. | 3 5 | Highest card, then second highest, 2 4 is the weakest and Q A the strongest. |
| High Card | Two cards of different suits that don't form any other hand. | 7 A | Highest card, then second highest, 2 4 is the weakest and Q A the strongest. |
As promised by "It was mostly made to calculate a bunch of probability and trying to make a bot for it (it didn't work out)." here are a bunch of probabilities.
Those have been rounded and/or simulated so they probably won't add up to exactly 100% and might be slightly off.
| Hand | Probability | Cumulative probability (this or higher) |
|---|---|---|
| 7 & 8 Flush | 0.3% | 0.3% |
| 7 & 8 | 0.9% | 1.2% |
| 15 Flush | 1.5% | 2.7% |
| Straight Flush | 3.6% | 6.3% |
| 15 | 4.5% | 10.8% |
| Pair | 5.9% | 16.7% |
| Straight | 10.9% | 27.6% |
| Flush | 18.1% | 45.7% |
| High Card | 54.3% | 100% |
| Visible card | 7 & 8 Flush | 7 & 8 | 15 Flush | Straight Flush | 15 | Pair | Straight | Flush | High Card |
|---|---|---|---|---|---|---|---|---|---|
| A | 0.3% | 0.9% | 1.6% | 11.1% | 4.5% | 15.8% | 25.6% | 25.1% | 15.1% |
| 2/3 | 0.3% | 0.9% | 1.6% | 11.2% | 4.7% | 15.8% | 26.6% | 24.3% | 14.6% |
| 4 | 0.3% | 0.9% | 1.6% | 10.9% | 3.8% | 15.8% | 22.8% | 27.5% | 16.5% |
| 5 | 0.3% | 0.9% | 16.5% | 10.1% | 34.8% | 10.1% | 13.4% | 8.6% | 5.2% |
| 6 | 0.3% | 0.9% | 5.4% | 10.4% | 12.9% | 14.4% | 19.3% | 22.7% | 13.6% |
| 7/8 | 4.2% | 11.1% | 1.6% | 6.8% | 4.5% | 15.1% | 16.7% | 25.1% | 15.1% |
| 9 | 0.3% | 0.9% | 5.4% | 10.6% | 13.6% | 14.4% | 22.1% | 20.4% | 12.2% |
| 10 | 0.3% | 0.9% | 5.2% | 10.8% | 10.1% | 14.4% | 21.9% | 22.7% | 13.6% |
| J/Q/K | 0.3% | 0.9% | 5.2% | 10.9% | 10.4% | 14.4% | 22.8% | 22% | 13.2% |