BlockDrop — Free Online Block Puzzle

Rules: a full horizontal line disappears

The playfield is a well 9 cells wide and 18 tall. Four-cell pieces fall in one at a time and lock in place after resting briefly on the floor or on other blocks. When a horizontal line is completely filled, it is cleared and everything above drops down by one row.

There are seven pieces, which QuizLab gives its own names: the pole, the cushion, the hat, the left and right bolts, and the left and right hooks. They are shuffled in bags of seven and dealt in order, so you never suffer an endless drought of one shape; the longest possible wait for a pole is about twelve pieces.

Clearing one, two, three or four lines at once is called a single, double, triple or quad, and the quad scores by far the most. Clearing on consecutive pieces adds a chain bonus, and every ten lines raise the level and the falling speed. If a new piece cannot appear because its spawn area is blocked, the game ends.

Controls: the irreversible hard drop gets its own gesture

• Keyboard: ← and → move, ↓ soft drop (faster fall while held), ↑ or X rotate clockwise, Z rotate counter-clockwise, Space hard drop, P or Esc pause.
• Holding a direction starts auto-repeat after 0.17 seconds, then moves one cell every 0.04 seconds.
• Touch: a short tap rotates, dragging sideways moves the piece cell by cell under your finger, dragging down soft-drops and flicking up hard-drops.
• Hard drop is mapped only to an upward flick, because mixing it with the downward drag would let one slip ruin a whole game.

Strategy: keep the surface flat and leave one column open

Games that last have one thing in common: a flat top surface. When neighbouring columns differ by more than two cells, only the pole can fill the gap, and you end up placing other pieces in bad spots while you wait for it.

If you are going for quads, keep one edge column empty and fill the other eight columns four rows high. With a nine-wide well, two pieces often fit eight cells exactly, and when the pole arrives you drop it into the open column to clear four lines at once.

The first rule is never to create holes, meaning empty cells covered from above. A hole stays until every line over it is cleared. Get into the habit of deciding where the current piece goes together with the next-piece preview, and holes become far less common.

History: from the mathematics of four squares to the arcade

Shapes made by joining squares edge to edge are called polyominoes. The American mathematician Solomon Golomb named and studied them in 1953, and tiling a rectangle with the twelve five-square pentominoes is still a classic puzzle. Counting mirror images separately, exactly seven distinct shapes can be made from four squares, which is why falling block puzzles have seven pieces.

The genre of dropping these four-square shapes to clear lines was first created in the mid-1980s on a research institute computer in Moscow, then spread around the world through home consoles and handheld systems. Rules so simple that anyone could grasp them regardless of language are usually credited for its success.

In the 2000s, ideas such as dealing pieces from shuffled bags of seven and a short lock delay after landing spread across the genre, shifting results away from luck and toward skill. QuizLab follows that direction while choosing its own 9×18 board size.

Questions about levels and piece handling in BlockDrop

Can I hold a piece for later?

No. There is no hold slot; you have to place every piece as it arrives. Instead, the next-piece preview lets you plan one step ahead, and because pieces come from bags of seven, you can also reason about which shapes are still left in the current bag.

What changes as the level goes up?

The level rises by one for every ten lines cleared, and with it pieces fall faster. Higher levels leave less time to think, so habits that keep the surface flat at low levels are what decide how far you get later.