Built Deck, explained

Built Deck is the mode where you bring your own cards. The chess half of the game is unchanged; the cards half has four parts to keep track of: a hand, a draw pile, a discard pile and a Braincells pile. Once you know how a card moves between them and what each turn does to them, the mode stops feeling like bookkeeping and starts feeling like a plan. Here is the whole cycle, from the first seven cards to the turn your pile runs dry.

The deck you bring

A deck is exactly 52 cards. You can hold up to three copies of any card, with one exception: Braincell, the currency card, which you can run as many of as you like. A deck with fewer than 52 cards is a draft. You can save it and keep editing, but you can't start or join a game with it.

The five starter decks the game gives every account each have 32 other cards and 20 Braincells, which is as good a shape as any to begin with. Building your first deck is about changing it.

Against a robot, the robot brings a random deck of its own, shuffled fresh each game: 32 cards drawn from the catalog plus the same 20 Braincells.

The opening hand

You start with seven cards. Before anyone moves, the game asks whether you want to keep them. If you don't, you can shuffle the hand back into your pile and draw seven new cards, as many times as you like. The cost comes when you settle: for each redraw you took, you put one card from the hand you keep on the bottom of your draw pile. So one redraw leaves you six cards in hand, two leaves you five, and so on.

Redraw a hand with no Braincells in it, or a hand that's all five-cost cards you won't afford for a long time. Keep a hand with two or three Braincells and something cheap to do with them.

Once both players have kept, the clock starts and White moves.

A turn, card by card

Each of your turns begins with a deal. If you hold fewer than seven cards and your pile isn't empty, the top card comes into your hand. That means on turn one, with a full hand of seven, nothing is dealt. There's no manual draw; the deal happens on its own, once a turn.

Then you have to make a board move. Every turn needs one. Along with it, before or after, you may play one card, and only one. A few cards say on their face that they don't use your card for the turn: Sugar Rush and Espresso Shot are the two, and they exist to give you Braincells to spend on the card you then play.

Cards marked as Instants are the other exception. Flash Shield or Countermand can be played during your opponent's turn, when the thing you want to answer is actually happening. Nothing pauses while you do; the clocks keep running.

When you end your turn you must be holding seven cards or fewer. If a card like Hostile Takeover has filled your hand past that, you discard down first. Hoarder lets you skip that once, and Big Pockets stays in play and raises your limit by two.

Where the cards go

Every card you play goes somewhere, and where matters.

A card you play for its effect goes to your discard pile, face up. So does any card you discard to a cost or to the hand limit, and any card your opponent knocks out of your hand with Pickpocket. The discard pile isn't dead. Dumpster Dive takes back the top card of it; Second Chance lets you search it for a specific card. Your opponent can dig in it too, with Rival's Trash and Grave Robber, so a strong card you've used once is a card they may use next.

A Braincell you play goes to your Braincells pile, not the discard. That pile is your bank. When you pay for a card, the Braincells you spend move from the bank into your discard pile, where Brainstorm can return them all to the bank and Recollection can take them all back into your hand.

Actives are the third destination. A card marked as an Active, like Efficiency or a face-down Bear Trap: e-file, stays in play in your actives pile with its ongoing effect instead of being discarded, until something such as Dispel removes it.

Braincells, the economy

The number on a card is its cost in Braincells. Costs run from one to five. Most of the catalog sits at two or three; only two cards, Purge and Hostile Takeover, cost five. You can only spend what you've banked, and you bank by playing a Braincell as your card for the turn.

That makes the early turns a choice. Banking a Braincell is a turn in which you played no other card. Playing a two-cost card is a turn in which you spent two earlier turns' worth of banking. The whole mode turns on judging when a card is worth the Braincells it took to afford, and Spending Braincells is about that judgment.

Braincells have a second use: on your own turn, one Braincell buys thirty seconds on your own clock, as many times as you can afford. In a ten-minute game that's often the difference between finding the move and flagging.

Several cards reach into the economy directly. Brain Drain takes a Braincell from your opponent's bank onto yours. Mental Block stops them spending any on their next turn, though they can still bank one. Overclock stays in play and makes every Braincell you bank from then on worth two.

Costs beyond Braincells

Some cards show small icons under their cost on the card's edge. Those are extra costs, all paid when the card is played. A card icon means you discard other cards from your hand, your choice. A skull means you sacrifice one of your own pieces. A gift means you give one of the pieces you've captured back to your opponent, who gets it back on the board.

Blood Oath costs one Braincell and one of your pieces, for two extra moves. Ransom hands back the piece you most recently took and pays you three Braincells for it. All In wants a Braincell, a card, a piece and a give-back, and gives three extra moves. Paying with pieces goes through when those prices are right.

When the pile runs dry

Fifty-two cards is a lot, but a long game will get through them. When your draw pile is empty, the start-of-turn deal simply doesn't happen. There's no reshuffle of the discard pile and no penalty. You play on with whatever is in your hand, and the game becomes chess with the cards you have left.

Unless your opponent has played Mill. That card is a curse: if you ever end a turn with an empty draw pile while it's on you, you lose the game. Its sibling Mind Blank does the same for an empty hand. Against a deck that runs either, the Braincell you were saving may need to stay in your hand rather than your bank.

What your opponent can see

Your hand is private. Your opponent sees how many cards you hold, as a fan of card backs, but not what they are. Your draw pile is private to both of you; even you only see its count, since knowing the order would tell you your next card. Your discard pile, your Braincells pile and your face-up actives are public.

A few cards lift the curtain. Reconnaissance shows your opponent's hand for the rest of your turn. Cash In banks every Braincell card in your hand at two apiece, but leaves your whole hand open to them until your next turn. A face-down trap is the one thing in your actives pile they can't read: they see that something is there, and nothing more.

The game's end

A Built Deck game ends the way any chess game does: checkmate, a clock running out, resignation, or a draw. The cards add their own endings, the curses above and the mines among them, and they add the last stand, where a mated player with a card still to try gets one more turn. Read the article on keeping your king safe before you learn that one the hard way.