Provably fair

The algorithm

ticket = HMAC_SHA256(server_seed, client_seed + ":" + nonce)
         -> take first 13 hex characters (52 bits)
         -> parse as integer
         -> modulo 1,000,000            => ticket in [0, 999999]

• Each item in a pack owns a contiguous slice of the 0–999,999 ticket space. The slice widths are the odds — the published percentages are derived from them, not stored separately.
• You see sha256(server_seed) before you open. The seed itself stays secret until you rotate it.
• The nonce increments on every open, so no two opens can share a result.
• Your client seed is yours to set. Change it whenever you like.
• Rotating reveals the old server seed, at which point every past open under it can be recomputed by anyone.

HMAC rather than a plain sha512(client:server:nonce) concatenation, which is vulnerable to length-extension.

The other games

Every game draws from the same ticket wheel above. What changes is how the wheel is read.

• Battles. The house commits a server seed when the battle is made and every seat adds its own client seed on joining. When the last seat fills, the battle’s client seed becomes the hash of the seat seeds in order and every round is drawn at once — nobody, including us, can know the result before the last player sits down.
• Deals. One ticket, one item. The odds you pick own the first odds × 1,000,000 tickets; the chase wins if the ticket lands inside them. The price is odds × item value ÷ 0.92, so the house keeps 8% wherever you put the slider.
• Draw. Ninety tickets are reserved when a round is dealt — ten rungs by nine lines, at nonce = base + rung × 9 + line. A line gets through a rung when its ticket falls under that rung’s per-line chance. Because only one line can ever be claimed, each rung stores the chance that at least one line survives it, taken from the prizes actually dealt; with k lines still standing each rolls against 1 − (1 − P)^(1/k). That is what makes every rung from the first up worth the same 95% of your stake — stopping early costs you nothing, and climbing is never a tax.

Equal odds changes everything, on purpose

The other mode on a pack page is the opposite of Spin for Gold: it really does change the draw. Turn it on and every prize in the pack gets the same chance — 1 ÷ n each — instead of the printed odds. The ticket wheel is untouched: same committed server seed, same client seed, same nonce, same number out. What changes is the map from that number to a prize.

The prizes are laid out dearest first, each taking floor(1,000,000 ÷ n) tickets, and the cheapest prize absorbs whatever tickets are left over by the rounding — never the dearest, which would make “equal” quietly favour the jackpot. You can recompute the whole table from the item list; nothing about it is stored.

It costs more because the average prize is worth more. The price is the expected value of the flat draw divided by the same return the pack already runs at, so the house keeps exactly the same share in either mode. Equal odds is a different shape of bet — many small chances at everything instead of one long shot at the best thing — not a better or a worse one. Your pack history records which mode each opening was bought in, and the price you actually paid.

Spin for Gold changes nothing

A prize worth ten times the pack rides up the reel behind a gold seal instead of its own photograph, and when one lands you press once more to see which it is. Worth being blunt about, because a second spin looks like a second chance and it is not one: the ticket chose your prize before the first reel turned, from the committed seed and the nonce, and the gold spin re-runs the same reel over the gold prizes only until it stops on the one you already hold. It cannot change the result, it costs nothing, and it is impossible to lose it — close the tab mid-spin and the prize is still in your inventory.

So the percentage printed under a prize is its real chance per open, sealed or not. There is no second draw, no boosted mode, and no odds we do not publish. Every sealed prize is marked with the seal on the pack’s own grid, at its true chance, before you spend anything.