Every domino in this deckbuilder has two ends.

Double Sixes takes the run based, score chasing structure you know from deckbuilders like it and rebuilds it from the pips up around dominoes instead of cards. Match ends, branch off doubles, and chase bigger and bigger chains for score that snowballs the way a good combo should.

BUILD THE CHAIN Drag tiles from your hand onto the board and match pips to the open ends of your chain. Doubles don't extend the line, they branch it, and every one you land pushes your multiplier higher. Get boxed in with nothing legal to play and you're not stuck: you're blocked, just like real dominoes, and a relief tile keeps the round moving.

SCORE THE COMBO In Boss rounds hit 'Play Chain' and watch your pips turn into Score × Multiplier. Long chains, stacked doubles, and enhanced tiles  Gold, Iron, Crystal, Prismatic, Charm & Slate all pile bonuses on top of each other. Discard the tiles that don't fit your chain and hunt for the ones that do, all within a limited number of plays per round.

DUEL FOR KEEPS Not every fight is a score attack. Duels put you across the table from a real rival: take turns playing matching tiles, draw from the boneyard when you're stuck, and race to empty your hand first. Choose Safe for a single, lower-stakes opponent, or Risky to face two rivals at once for a bigger payout and lose a duel, and the run ends there.

SEVEN BOSSES, SEVEN TWISTS Every act builds toward a boss tied to one of the seven double tiles, and each one bends the rules of the round in a different direction, smaller hands, no discards, capped chain length, locked pips, disabled double bonuses, and worse. The final boss, The Twin, turns the whole format on its head: a duel against two rivals at once, winner takes the run.

RELICS, ANCIENT DOMINOES, AND A SHOP THAT REWARDS RISK Spend your winnings between fights on new tiles and relics that reshape how your chains score big-chain builds, all-doubles builds, economy builds that turn cash itself into multiplier. Beat a boss and you'll walk away with more than bragging rights: unique, boss-exclusive dominoes that echo the fight you just won.

RUN AFTER RUN No two hands play the same. Build around a stack of doubles one run and a lean, efficient chain the next, unlock new relics and tiles as you go, and see how far you can push a rack of dominoes past where anyone expects them to go.