Kerslide
Kerslide › Guides › History of block puzzles
A short history of block puzzles
From mathematicians' polyominoes to falling blocks to calm grid puzzles, and the one rule Kerslide adds.
▶ Play free In your browser · no download · no sign-up
Kerslide belongs to a family of games that is older than video games: puzzles about fitting shapes made of squares into a grid. Here is a short history of that family, and where Kerslide's twist fits in.
Polyominoes: shapes made of squares
The shapes in block puzzles have a mathematical name: polyominoes, figures made by joining equal squares edge to edge. The term was coined by the mathematician Solomon W. Golomb in 1953, and the shapes became widely known through Martin Gardner's recreational mathematics columns in Scientific American, beginning in 1957. Golomb later collected the subject in his book Polyominoes (1965).
A domino has two squares, a tromino three, a tetromino four and a pentomino five. Kerslide's pieces are all polyominoes: a single square, the two- and three-square lines, tetrominoes such as the 2×2 square, L, T and S/Z shapes, and the five-square corner (a pentomino often called the V). You can see all of them in the piece guide.
Tiling puzzles
Long before screens, people played with physical sets of these shapes: can you fill a rectangle with all twelve pentominoes? Puzzles like this are about fitting pieces together with no gaps. That idea, fill the space without leaving holes, is still at the heart of every block game.
Falling blocks
In 1984, Alexey Pajitnov created Tetris at the Academy of Sciences in Moscow. It added time pressure and one crucial mechanic: a completed row disappears. Clearing lines to make room became the core loop of an entire genre.
Place-anywhere grid puzzles
Much later, a calmer style became popular on phones: you are given a few pieces, you can place them anywhere on a square grid, and completed rows and columns clear. Games such as 1010! (2014) made this format widely known. There is no gravity and no timer; the challenge is planning, because pieces cannot be rotated and you must always find room for the next ones.
Kerslide's twist: the board moves
Kerslide keeps the calm, place-anywhere format and adds one rule: every clear moves the whole board one cell, right after a row clear and down after a column clear, and blocks pushed past the edge disappear. That small change means:
- a clear changes the position of every other block, so you think one move ahead;
- the right and bottom edges become exits, so blocks can leave without being cleared;
- the board drifts in one direction, so where you place pieces matters, not only whether they fit.
It is still a puzzle about fitting shapes into a grid, the same question Golomb's polyominoes asked seventy years ago, but with a board that never stays still. Read how the shift works, or just try it.
More guides: all guides · How to play · Tips