The Basics
TETRIS FORGE is three-dimensional Tetris. Pieces fall along the Y axis (downward) into a rectangular well measured in width × height × depth (X × Y × Z). You move and rotate each piece on the horizontal X/Z plane before it locks into place.
Unlike classic 2D Tetris, you can tilt pieces in 3D with extra rotation keys, navigate depth with W/S, and orbit the camera around the well to read the stack from any angle.
The goal is to fill horizontal layers — entire Y-slices of the well floor — to a configurable percentage (default 80%). When a layer meets the threshold, it is forged away: all cells on that level are cleared and everything above drops down. Multiple layers can clear from a single lock. Game over occurs when a new piece spawns overlapping locked cells.
Game Modes
Choose a mode on the title screen or from the sidebar dropdown before starting a new game. Each mode sets the well size, gravity speed, scoring multiplier, and whether forge assists are available.
6×12×6 well · 800 ms gravity · forge assists · boosted visual effects · 1× score. The default mode — faster clears and helpful power pieces.
8×16×8 well · 1000 ms gravity · no assists · standard effects · 1× score. The full-size well for purists who want zero help.
5×10×5 well · 600 ms gravity · forge assists · boosted effects · 1.5× score. Compact well, blazing speed, highest score potential.
Layer Clear Threshold
Use the Layer Clear slider in the sidebar (50%–100%, default 80%) to set how full a layer must be before it forges. Lower values mean easier clears; 100% requires every cell on a layer to be filled. The setting applies immediately and affects all future clears in the current session.
Custom Well Size
Between games you can resize the well by dragging the corner grips on the wireframe boundary (visible at the edges and corners of the 3D well). Wells can range from 4×6×4 up to 16×24×16, but cannot shrink below the space occupied by locked blocks and the active piece. Selecting a mode preset resets the well to that mode's default dimensions.
Pieces
Seven standard 3D tetrominoes — each four mino cubes connected face-to-face in a single Y plane — plus three forge assist pieces in Arcade and Forge Rush modes.
Tetrominoes
Randomizer
Pieces are drawn from a 7-bag randomizer: every seven spawns contain one of each tetromino type before the bag reshuffles. This keeps distribution fair and predictable over long runs.
Hold & Next Queue
- Hold (Shift) — swap the active piece with the hold slot. Usable once per lock; after locking, hold resets for the next piece.
- Next — three upcoming pieces are shown in the sidebar so you can plan ahead.
Controls
These match the control hints shown in the in-game sidebar during play.
Mouse
Keyboard
Touch
Scoring & Progression
Layer Clears
| Layers forged at once | Base points |
|---|---|
| 1 layer | 100 × level |
| 2 layers | 300 × level |
| 3 layers | 500 × level |
| 4+ layers | 800 × level |
Final points are multiplied by the mode score multiplier (1× or 1.5× in Forge Rush).
Combos
Clear layers on consecutive locks without a miss in between to build a forge combo. Each combo after the first adds (combo − 1) × 50 × level bonus points and displays FORGE COMBO ×N. Failing to clear any layer on a lock resets the combo to zero.
Drop Bonuses
- Soft drop — +1 point per cell moved down (keyboard or gravity-assisted while holding ↓).
- Hard drop — +2 points per cell of drop distance.
- Hammer streak — hard-drop three or more pieces in a row without a non-hard-drop lock between them to trigger a streak bonus of 15 × streak length points.
Layer Milestones
After each lock, the game checks your best-filled layer:
- 75% filled — LAYER PRIMED toast, +25 points (once per layer height).
- 90% filled — ALMOST SEALED toast, +50 points (once per layer height).
Milestone tracking resets when that layer is forged away.
Level & Speed
Level increases by 1 for every 10 total lines (layers) cleared. Gravity speeds up by 80 ms per level, down to a minimum of 50 ms between drops. Base gravity depends on mode: 600 ms (Rush), 800 ms (Arcade), or 1000 ms (Classic).
Forge Assists
In Arcade and Forge Rush, there is a 9% chance each spawn is a special assist piece instead of a normal tetromino. Classic 3D never spawns assists. Each assist is a single glowing cube that triggers an effect on lock.
Advanced Tips & Techniques
Reading the Stack in 3D
- Orbit the camera (LMB on empty canvas) to inspect depth — the isometric default hides gaps along the Z axis.
- Watch the ghost piece to preview landing position before committing.
- The floor grid inside the well shows cell boundaries; use it to align I-pieces across an entire layer.
Layer Forging Strategy
- Focus on one layer at a time — the Layer Progress bar tracks your best candidate for the next clear.
- Lower the clear slider (e.g. 70%) for faster forging in custom wells; raise it for a harder challenge.
- Set up multi-layer clears by filling two or more Y-levels to threshold simultaneously — worth 300–800 base points before level multiplier.
- Chain clears back-to-back to build combos; even a single-layer combo streak adds meaningful bonus points at higher levels.
3D Rotation & Wall Kicks
- Use R/F (X) and Z/C (Z) to flip a piece onto a different face — essential for fitting into 3D cavities.
- When rotation is blocked, the engine tries sliding the piece ±1 on X, Z, or Y before rejecting — use this to squeeze through tight gaps.
- Rotate early during lock delay to maximize adjustment time before the piece seals.
Hold & Queue Management
- Hold an I-piece while building a layer, then release it to sweep a full row when nearly complete.
- Remember: hold is once per lock — don't waste it on a piece you can place immediately.
- Glance at all three next pieces to plan two moves ahead, especially in Forge Rush where speed is punishing.
Speed Techniques
- Hard drop (Enter or MMB) for instant placement when you are confident — builds hammer streaks.
- Soft drop (↓) for fine control with a small point bonus per cell.
- Mouse drag lets you reposition quickly without repeated key taps — combine with RMB (Y) or 2x RMB (Z) for fast rotation.
- DAS/ARR lets you hold movement keys to slide across the well during lock delay.
Starting a Game
- Click a mode card on the title screen, or pick a mode from the sidebar and press NEW GAME.
- After game over, the button becomes FORGE AGAIN — stats appear in the sidebar panel.
- Click the canvas to ensure keyboard focus; the game captures keys only when the canvas is focused.