The portfolio
You can read every rule of a card game and still not know whether there is anything to decide in it. That only shows up a few minutes in, the first time an obvious move turns out to have cost you something.
So these games are here to be played, not read about. Each one loads the real engine into this page, with no account. What is written under each game says where to look while you are playing; the rules are in the game.
In a real match both players are dealt the same randomness, which is the whole argument for comparing two scores at all. That argument is on its own page.
Pyramid solitaire, streak-scored
39 slots · 4 hidden layers · 14-stack stock, face up · 1 joker
A chain doubles with every card you add, so the fourth card is worth more than the first three together. The legal move sitting in front of you is almost never the expensive one, and once a chain is running up or down in rank it has to keep going that way — so the direction you commit to early is most of what the hand is worth.
One grid, ten poker hands
5×5 grid · 25 placements · 10 hands scored · 4 discards
Every square is scored twice, once down and once across, so the card that completes a row is also a card you just spent on a column you were building into something else. No placement does only one thing, and the discards do not buy you out of the trade: the deck moves on whether you used the card or not.
Bid and trick-take, in duplicate
13 cards · 3 bots · none of them carries RNG
You bid with your partner’s hand face up, so what you are setting is what the two of you can actually take — and then you have to land on it exactly. A trick too many costs the same as a trick too few, which turns the end of the hand into the problem of getting rid of winners you no longer want.
Duplicate hold'em, five hands
5 hands · 3 decisions a hand · bet chosen blind
You size the bet before you have seen a card, so every decision after it is about a hand you have already paid to be in. Checking is free at each of them but one: reach the river having raised nothing all hand, with a raise you could still afford, and the option is gone — raise or fold.
Blackjack, played with dice
36 dice · 6 of each face · none held back · dealer stands at 11
Nothing is held back from the shoe, so every die you have seen is a die that cannot come again. Late in a match you can work out what is left instead of guessing at it, and that is what decides whether doubling, splitting a pair or chasing a three-die thirteen is worth what it costs.
Push your luck, or bank it
5 turns · no undo · insurance · one ×2 a match
Each roll you choose between banking the pile and risking it, and a roll that scores nothing takes the whole pile with it. Both things you can buy are timing problems: insurance covers only the very next roll, so a beat early is money for nothing, and the one multiplier a match is worth whatever you dare put under it.
Answer the card, or let the deck answer
52 cards · 5 in hand · 3 outcomes · bank whenever you like
Lay a card from your hand and you survive for certain and score nothing. Run it and the deck answers for you — it pays, or it pushes, or it ends the match at zero. Which is why the decision that matters is when to stop: you can bank whenever you like, and what you have stops with you.
Four columns, one deck, hit 21 exactly
4 columns · 50 live cards · 2 burned, never seen · 2 discards
A placement pays ten, a column landing on exactly twenty-one pays a hundred a card, and a column that goes over costs five hundred. Read those three numbers together and the move nobody expects falls out of them: against a board where nothing fits, busting a column on purpose is a purchase — about four hundred and ninety, for somewhere to put the next card.
The two questions that follow are how a result gets established, and what it takes to put one of these in front of your own players. Each has a page.
