HOW TO PLAY

Ideal Tris is a free falling-block puzzle game that runs in your browser — no download, no install, no account. Pieces made of four square blocks fall into a 10×20 well. Your job is to rotate and place them so they form complete horizontal rows. A complete row clears, everything above it drops down, and you score points. If the stack reaches the top of the well, the game is over.

That one rule hides a surprising amount of depth. This page covers the controls, the pieces, how scoring works, and what each of the six game modes asks of you.

CONTROLS

Holding left, right, or down repeats the move automatically after a short delay — this is the classic delayed auto-shift (DAS) that lets you slide pieces across the board quickly without hammering the key.

THE SEVEN PIECES

Every piece (called a tetromino) is one of seven shapes, each with its own classic color: the cyan I (the long bar), yellow O (the square), purple T, green S, red Z, blue J, and orange L. A faint ghost piece at the bottom of the well shows exactly where the current piece will land, and the NEXT panel previews what is coming so you can plan ahead.

The HOLD box stores one piece for later. Press hold to swap the falling piece into the box; press it again on a later piece to swap them back. You can hold once per piece — use it to bank an I-piece for a big clear or to escape a piece you have no good spot for.

SCORING

Clearing more rows at once is worth far more than clearing them one at a time. Every award below is multiplied by (level + 1), so the same clear is worth fifteen times more at the top level than at the start:

Two bonus systems reward advanced play:

• T-spins — rotating a T-piece into a slot it could not simply drop into scores 400 base points even with no line clear, and 800 / 1200 / 1600 for T-spin singles, doubles, and triples. See the strategy guide for how to set these up.
• Combos — clearing lines with consecutive pieces adds a growing bonus of 50 × combo count × (level + 1) on top of each clear.

LEVELS AND SPEED

In modes with level progression you advance one level for every 10 lines cleared, across 15 levels. Gravity follows the classic NES speed curve: pieces take 800 ms per row at level 1 and only 50 ms per row at level 15, where they arrive at the floor almost instantly. The lock delay — the brief window to slide or rotate a piece after it touches down — also shrinks as you climb, from half a second early on to a tenth of a second at top speed.

THE SIX GAME MODES

• Marathon — the classic score attack. Start at level 1, survive the rising speed curve, and post the biggest score you can. Leaderboard ranks by score.
• Countdown — Marathon in reverse. You start at maximum speed and every 10 lines slows the game down one level. Survive the brutal opening, clear 150 lines total, and your finish time goes on the board. Fastest time wins.
• Sprint — clear 40 lines as fast as possible at a fixed, gentle speed. A pure efficiency race; the leaderboard ranks by time.
• Blitz — score as many points as you can in exactly two minutes. Levels still rise as you clear lines, so fast play compounds: higher level means higher multipliers before the clock runs out.
• Cheese Race — the board starts pre-filled with 10 rows of garbage, each with holes punched in it. Dig down and clear all the garbage as fast as you can. Fastest time wins.
• Master — maximum gravity from the very first piece, forever. No score, no timer — the leaderboard simply ranks how many lines you survive.

Each mode keeps its own global top-10 leaderboard. When you place, you can enter a name up to 14 characters — no account needed.