You never place anything in a match-3 game. The grid arrives full, every square already occupied, and the single verb is to trade two neighbours and hope the trade lines up three of a colour. Matched tiles vanish, everything above them drops into the hole, and the drop often makes further matches without you. That restriction — no placement, only exchange — is where the rest of the genre comes from.
Compare it with the falling-block games it descends from. In Tetris the empty space is the resource: pieces arrive, you place them, you lose when you run out of room. A match-3 board has no empty space to manage. You are not filling a container — you are editing one that is already complete.
Eugene Alemzhin's Shariki, a free DOS game from 1994, is where the swap first appears; Bejeweled (PopCap, 2001) is the version that shipped. Neither invented matching by colour — Columns and Dr. Mario had done that — but they deleted the queue of incoming pieces, and with nothing left to place, all your attention goes to reading the board in front of you.
That is harder than it sounds, because the board keeps changing after you act. Refills fall from above, gravity resolves, and chains can run for several beats on their own. Scoring the swap you can see is beginner play. Reading what the refill will drop into the hole you are about to make is the skill.
Here is that loop with nothing attached to it — six columns, four colours, no specials, no move limit, no goal beyond a tally of tiles cleared. Everything else on this page is something a designer bolted on afterwards.
Tap two adjacent tiles to swap them — line up three of a colour
The first bolt-on makes longer matches worth chasing. Three in a line clears and does nothing else, so the interesting swaps are the ones that reach four, five, or a corner.
| Match | Makes | In which games |
|---|---|---|
| Three in a line | The tiles clear. Nothing survives. | Universal — the one rule the whole genre shares |
| Four in a line | A striped sweet that clears its entire row or column | Candy Crush |
| Five in a line | A colour bomb — swap it and every tile of that colour goes | Candy Crush |
| An L or a T | A wrapped sweet that detonates the squares around it | Candy Crush; Bejeweled answers a corner with a Star Gem |
Read the right-hand column, because it holds the most-copied mistake in the genre. Those are Candy Crush Saga's rules, published in 2012 and imitated so widely they get mistaken for physics. Bejeweled answers the same corner with a Star Gem that clears a row and a column at once, and a game you build is free to answer it with something else. The only inherited rule is three.
The ceiling sits above the table anyway: swapping two specials into each other so they detonate together. That is where a board's best players live, and it is the one move a new player cannot stumble into by accident.
Everything so far fits in a browser tab. What made match-3 the shape of an industry is the layer around it — a level with a goal (score this, clear that jelly, escort an ingredient to the bottom row), a move budget, a map threading hundreds of those levels, lives that refill on a timer, a shop selling boosters. Match-3 is the one puzzle genre with a proven free-to-play model attached, and that model is why these games look the way they do.
Two branches grew from it. Playrix's Gardenscapes: New Acres (2016) spends each cleared level on the next beat of a garden renovation, so the puzzle funds a story with no tiles in it. Puzzle Quest (2007) and Puzzle & Dragons (2012) went the other way and made the board a resolution system — skulls deal damage, colours charge a spell — proving the grid can sit under a role-playing game the way dice do.
The catch: the wrapper is also where the genre earned its reputation. Lives that lock you out mid-streak, a booster offered at the precise moment of failure, difficulty spikes placed to lean on your patience — the machinery that makes the loop feel generous is the same machinery tuned to sell you past it. At its worst you cannot tell whether a level is testing your skill or your wallet. Inherit the wrapper wholesale and you inherit that too. The same pressure shapes idle games, and the two have been borrowing each other's furniture ever since.
Cascades cut the same way. Free matches raining down after one good swap is why people love this, but if the rain decides the level then your decision did not. Tune it so a deliberate swap beats a lucky one over any stretch longer than a few moves. Logic puzzles sit at the opposite pole — no gravity, no refill, nothing random at all — while word puzzles take the same daily-habit slot with language as the material.
Two games can both be match-3 and share almost nothing. Say which one:
Type: Match-3 (a full board — you trade two tiles, never place one)
Core loop: Read the board the cascade left, swap for the biggest
consequence, reach the goal inside the move budget
Perspective: 2D grid, front-on, gravity pulling everything downward
Win / lose: Win on the level's goal — score, jelly, an escorted ingredient;
lose by spending the last move
Session: A level in a minute or two; the map is what brings you back
Progression: Level maps, a bestiary of blockers, boosters, a lives economy
The three lines worth arguing over are the goal list, the cascade tuning and the price of failure. The swap itself has been solved since 1994.