Fighting beyond the edge

A chessboard has sixty-four squares, and every plan you have ever made on one assumes that number is fixed. Two cards in the Built Deck catalog break that assumption. Break Ground and Breakout open a strip of ground just past one edge of the board, and once it's open, it's board: pieces stand on it, slide across it, capture on it and get captured there. Study Hall's "Beyond the edge" topic walks you through the two cards on a practice board. This article is about what to do with them once you've seen them work, and about the games where opening the edge turns out to be a favor to your opponent.

What actually opens

Break Ground costs three Braincells. You pick a square on the board's border, and the rank or file just beyond that square opens for the rest of the game. Choose a square on the h-file and a new file appears past it, labeled I. Choose a square on rank 8 and a new rank 9 appears above it. The same works past the a-file and below rank 1. Four edges, one card each, and nothing closes them again. There is no card in the catalog that seals an edge once it's open, so treat the decision as permanent, because it is.

Breakout costs four and does two things at once. It opens the ground beside one of your own pieces that is already standing on the border, and it marches that piece out onto the new square in the same action. The catch is in the card's last line: this is your move for the turn. The march is the turn's board move, not an extra on top of one, so Breakout is for turns when the march itself is the point.

Either way, the new squares belong to nobody. The player who opened the edge has no special claim on it. Your opponent's rook can slide out there as happily as yours, and that fact decides most of what follows.

Sliding pieces grow, knights don't

The piece that gains the most from an open edge is the one that moves in straight lines. A rook on an open rank 9 attacks the whole of that rank and still looks down its file into the board proper. A bishop finds a ninth diagonal square. A queen gets both. These pieces were already strong because they covered distance, and distance is exactly what an open edge adds.

A knight gains almost nothing. Its jump is fixed, so a new rank gives it one or two more landing squares and no more reach. A king gains a square to step to, which sometimes matters a great deal, and we'll come back to that. Pawns are the odd case, so they get their own section.

So before you open an edge, count the long-range pieces on each side. If your opponent has both rooks and you have one, a new rank is more theirs than yours. If you are the one with the queen and they've lost theirs, open ground is your playground. The board gets bigger for both players, but it gets more useful for whoever has more pieces that use length.

Pawns and the moving finish line

A pawn promotes when it reaches the last rank. When rank 9 is open, the last rank for White's pawns moves out to rank 9, and the same happens for Black at rank 0 when that edge opens. A white pawn that would have become a queen on rank 8 now has one more step to take.

This is the most common way an opening backfires. You open rank 9 to give your rook room, and your opponent's pawn, two squares from promotion, is now three squares away. Or the reverse: your own pawn on the seventh rank was about to promote next move, you open the top edge for some other reason, and you've handed the defender a whole extra turn to deal with it.

Read it the other way, too. If your opponent has a pawn on the sixth and you have no way to stop it, Break Ground on that edge is a stall that costs three Braincells and buys you a move. That's an expensive move, but a queen on the board is more expensive.

The second thing to know about pawns past the edge is simpler: the new squares are board, so a pawn on the a-file or h-file can be marched out onto a new file with Breakout and keep walking from there. A pawn out on the flank is out of most pieces' reach, and its promotion square still sits at the far end of the board, so it's a slow but hard-to-stop runner.

Where the edge doesn't reach

Several cards treat the board as a shape, and they were all built for the 8×8 square. The rotations (Rotate 90° Right and the rest), Outer Ring Right, Inner Four Left and the Corner Shuffle Right family all turn or cycle the original sixty-four squares and leave the annex out. A piece sitting on an open edge stays where it is while the board inside spins.

That cuts both ways. A piece parked on the annex is safe from a rotation that would have dumped it somewhere useless, which makes an open edge a modest shelter against an opponent whose deck is built around turning the board. It also means a rotation won't carry your edge piece back into the fight, so if you've marched a rook out there and then rotate, it stays out there and may now be facing the wrong way for the position you've created.

Board-shape cards and edge cards are from different schools, and a deck that leans on both will keep tripping over itself. Pick one.

The king on the edge

A king can stand on an open edge like any piece, and the ground beyond the border is a legitimate flight square. If your king is being hunted along the back rank, a new rank 9 behind it is one more place to run, and an attacker who built a mating net for an eight-rank board has to rebuild it.

This is the best defensive use of Break Ground. Open the edge behind your king when the net is closing, not before; opened too early, the same squares help the attacker bring a rook around behind you. Open it the turn you need the flight square and the attacker is a tempo behind.

The reverse applies to your attack. Before you commit to a back-rank mate, ask whether your opponent holds Break Ground. You can't see their hand without a vision card, but you can see their discard pile and what's left in their deck size, and if they're playing a deck that has already shown you one Break Ground, assume a second. A mate that depends on the edge being an edge is a mate that one card undoes.

When to open, in order

Putting it together, the cases for opening an edge rank roughly like this.

1. Your king needs a flight square now, and the attacker's long-range pieces aren't placed to use the new ground this turn.
2. You have the long-range material advantage, especially rooks, and the open rank or file lets one of them attack along a line the defender can't contest.
3. Your opponent's pawn is about to promote and you have nothing else that stops it.
4. You want a piece out of the way of a rotation or shift you're about to play yourself.

And the cases against, which should stop you even when one of the above applies: your own pawn is about to promote on that edge; your opponent has more rooks and queens than you do; or the edge you'd open runs behind your own king while the attack is still a few moves off.

Breakout as a tempo trick

One last use for Breakout that doesn't show up on the card. Because it moves a piece and counts as your move, it's a legal way to make a move when the only normal moves you have are bad ones. A rook that would otherwise have to step into a fork can march out past the edge instead and come back when the fork has passed. Four Braincells and a card is a lot for a dodge, but it is sometimes the only dodge there is, and the ground it opens stays.

Opening the edge is the rare card effect that changes the board for the rest of the game rather than for a turn or two. Decide it the way you'd decide a pawn structure, and you'll find the ground past the border is usually working for you.