Articles

Everything worth knowing about stacking blocks: where the genre came from, exactly how the rules work, the technique that separates a good run from a great one, and how TETERI itself is put together.

114 articles across 7 sections

History of the genre

From a Soviet research computer in 1984 to a courtroom in California and a thirteen-year-old crashing an NES on stream — how block stacking became the most-ported game idea ever written.

• Who Invented Tetris?Alexey Pajitnov wrote the original in 1984 at a Soviet research institute, on a computer that could not draw graphics.
• Where the Name "Tetris" Comes FromA Greek numeral prefix welded to the name of a racquet sport, because the author liked both.
• The First Version Ran on a Computer That Could Not DrawThe Elektronika 60 had no graphics mode, so the original pieces were built out of punctuation marks.
• How the Game Escaped the Soviet UnionIt spread by informal copying, reached Hungary, and was picked up by a Western agent before anyone had signed anything.
• ELORG and the Most Confusing Licence in GamesA Soviet state agency, a chain of Western sublicences, and a fight over what the word "computer" means.
• The Trip to Moscow That Decided the Handheld MarketHenk Rogers arrived at ELORG without an appointment, and left with the rights that made the Game Boy.
• Why Bundling It With the Game Boy Worked So WellA monochrome handheld needed a game that lost nothing on a bad screen. This was the best candidate ever written.
• The Lawsuit Over Who Could Publish ItTwo versions on the same console, one of them recalled, and a ruling that turned on what had actually been licensed.
• How the Author Finally Got PaidThe rights reverted in the mid-1990s, and Pajitnov co-founded the company that has licensed the game ever since.
• The Specification That Made Every Modern Version Feel the SameRotation, kicks, the seven-bag, hold and scoring were unified into one rulebook — and it changed how the game is played.
• The NES Version and Its Beautiful FlawsNo hold, no kicks, a randomiser that can starve you, and a scoring table that made it a competitive sport anyway.
• How a 1989 Cartridge Got a World ChampionshipA small side event grew into a competitive scene that repeatedly broke what the game was thought capable of.
• Hypertapping and Rolling: Two Ways to Beat a Speed LimitWhen the game outran the d-pad, players changed how they held the controller rather than accepting the ceiling.
• The Kill Screen: When the Game Runs Out of NumbersPush a 1989 program past what its authors tested and the arithmetic starts producing nonsense, then it crashes.
• The Arcade Versions and What They ChangedA coin-op cabinet has different incentives to a home console, and the design shifted to match.
• Why It Ended Up on Absolutely EverythingTiny state, no assets, and rules you can implement in an afternoon — the most portable game design ever written.
• The Game on Screen: Documentaries, Dramas and ShorthandA 2023 thriller dramatised the rights fight, and falling blocks became visual shorthand for "computer".
• What Alexey Pajitnov Did NextHe kept designing puzzles, moved to the United States, and spent decades never quite escaping the first one.
• The Soviet Computing World the Game Came FromNo software industry, no home market, no way to sell a program — and a culture of copying that let one escape.
• Clones, Variants and the Genre That Grew Around ItRules are not copyrightable, so a whole family of falling-block games grew up alongside the original.
• Why the 1984 Design Barely Needed ChangingForty years of iteration refined the edges and left the centre alone, because the centre was already right.

Rules and mechanics

What the game is actually doing under the hood: rotation systems, wall kicks, lock delay, the seven-bag, and precisely how every point is scored.

• How the Seven-Bag Randomiser WorksPieces are not drawn at random. Every group of seven contains each shape exactly once, which makes the queue countable.
• The Super Rotation System, ExplainedFour defined states per piece and a table of fallback offsets, which is what lets a piece spin into a gap it should not fit.
• Wall Kicks: Why Your Piece Moved When You Rotated ItA blocked rotation tries a list of nudges before giving up. Knowing that list turns a quirk into a tool.
• Lock Delay: The Half-Second That Saves Your RunA landed piece does not lock immediately, and nudging it restarts the clock, up to a limit.
• The Ghost Piece and Why It Is Not CheatingThe outline showing where a piece will land removes arithmetic, not difficulty.
• How the Hold Slot WorksPark one piece for later, but only once per piece, which is what makes it a decision rather than an undo button.
• Hard Drop and Soft Drop: When to Use WhichOne slams and locks instantly, one accelerates and keeps your options open. They are not interchangeable.
• How Gravity Speeds Up, Level by LevelThe curve is not linear. It is gentle for ten levels, and then it stops being gentle.
• How the Game Knows You Did a T-SpinTwo conditions, checked when the piece locks: the last action was a rotation, and three corners are occupied.
• Perfect Clears: Emptying the Board CompletelyClear every block on the field at once and the bonus dwarfs everything else in the scoring table.
• The Back-to-Back Bonus, and What Counts as DifficultChain four-row clears and T-spins without an ordinary clear between them, and everything is worth half again as much.
• Combos: Clearing With Consecutive PiecesEvery piece in a row that clears something extends the chain, and the bonus grows the longer it runs.
• The Complete Scoring TableEvery value in the game, what multiplies what, and the order the bonuses apply in.
• DAS and ARR: The Timings Behind Holding a DirectionTwo numbers control how a held key moves a piece, and they change how the game feels more than any other setting.
• Exactly How a Run EndsNot when the stack looks full, but when a new piece has nowhere to spawn.
• The Seven Pieces, One by OneWhat each shape is good for, what it ruins, and why S and Z are the ones that end runs.
• Where Pieces Spawn and Why the Buffer ExistsA couple of hidden rows above the visible field give rotations somewhere to go.
• What Counts as a Difficult ClearA precise list, because the back-to-back bonus depends entirely on it.

Technique and strategy

How to stop topping out at level six. Stacking shapes, T-spin setups, openers, finesse, and the habits that quietly cost you every run.

• Keep the Stack Flat: The One Habit That Matters MostA flat surface accepts every piece. A jagged one accepts a few. Most runs end because the board stopped accepting what the bag offered.
• Never Bury a HoleA covered gap costs you every row above it. Taking a worse placement to avoid one is nearly always correct.
• Downstacking: How to Dig Yourself OutClearing your way down to a buried hole is a distinct skill, and it is the one that turns bad runs into recovered ones.
• The Nine-Column Stack and the Open WellFill nine columns flat, leave one open, and wait for the long piece. The standard shape for a high score.
• Six-Three Stacking and Why Some Players Prefer ItSplitting the board into two flat regions instead of one gives you somewhere to put the awkward pieces.
• Read the Queue, Not the Falling PieceIf you are deciding where the current piece goes while it falls, you are already too slow for level ten.
• Use Hold on Purpose, Not as an Undo ButtonThree good reasons to hold, and one very common bad one.
• Your First T-Spin: The Double SetupOne shape, three columns wide, worth more than a four-row clear. Learn this before anything else advanced.
• The T-Spin Triple and the Kick That Makes It PossibleThree rows from one T piece, using the most extreme offset in the kick table.
• Finesse: Placing Every Piece in the Fewest InputsThere is an optimal number of keypresses for every placement. Using more costs time you need later.
• Openers: Why the First Ten Pieces Can Be MemorisedThe board starts empty and the bag guarantees the pieces, so the opening is a solved problem.
• When to Take a SingleA single is the worst clear in the game and sometimes the correct one. Knowing which is a real skill.
• Overhangs and Tucks: Placing Pieces Under ThingsA covered space is not lost space. Rotation kicks can reach under an overhang that sliding cannot.
• Surviving High GravityAbove level twelve the piece is at the bottom before you have read it. What changes is where the thinking happens.
• Six Mistakes Almost Every New Player MakesThe specific habits that end early runs, and what to do instead.
• Plan in Sequences, Not PlacementsA piece that is awkward alone is often fine as the middle of a three-piece plan.
• How to Practise DeliberatelyPlaying more runs is not practice. Constraining a run so it isolates one skill is.
• Keyboard, Controller or Touch?The input device matters less than people claim, but it matters in specific and predictable ways.
• Building for the Pieces You Do Not WantS and Z arrive once per bag, guaranteed. A stack with nowhere for them is a stack that is about to fail.
• When to Abandon Your WellWaiting for the long piece is right until it is not. Recognising the switch separates careful play from stubborn play.
• Speed or Accuracy: Which to Work On FirstThey fail differently, and the symptoms tell you which one is actually limiting you.
• Reading the Danger LineA marker six rows from the top, and what to do differently once your stack crosses it.
• Counting the Bag: Knowing What Is ComingThe randomiser guarantees each shape once per seven, which makes the unseen pieces deducible rather than merely probable.
• Recovering From a Board That Has Gone WrongTwo holes, a spike and eleven rows of stack. There is usually still a run here if you stop trying to score.
• Why You Plateau, and How to Get Past ItImprovement is not smooth. You stall at a level because one specific constraint became binding.

Versus play

Garbage, cancelling, attack tables and pressure. Everything that changes when there is someone on the other side of the screen.

• How Garbage WorksYour clears become rows in your opponent's well, rising from the floor with a single gap in them.
• Cancelling: Why Attacking Is How You DefendYour outgoing attack eats incoming garbage before any of it lands. There is no defensive option.
• The Attack Table: What Each Clear SendsEvery clear type converted into rows of garbage, plus the bonuses that stack on top.
• Combo Pressure: Why Small Attacks Can Beat Big OnesContinuous garbage denies your opponent the quiet piece they need to survive.
• How to Open a DuelThe first twenty pieces decide more duels than anything that follows.
• Reading Your Opponent's BoardTheir well depth, their stack height and the shared queue tell you when their attack is coming.
• Defending When You Are BehindA tall stack and a full meter is recoverable, but not by playing carefully.
• Clean and Messy GarbageWhether the holes line up decides how survivable an attack is.
• Latency in Online Duels, and Why It Does Not Ruin ThemNothing about your own board depends on the network, which makes this genre unusually tolerant of lag.
• How to Beat the CPUIt stacks better than you and it never panics. What it does not do is adapt.
• Two Players, One KeyboardSplit-screen has a texture online play cannot reproduce, and a couple of practical quirks.
• Rematches, Tilt, and Playing the Next GameThe most common way to lose a set is to let the previous loss into the next match.

Playing TETERI

What this particular game does: its modes, its controls, how it runs offline, and why it asks nothing of you before you can play.

• Why Play TETERIFree, instant, offline-capable, and it asks nothing of you before you can start. A straight account of what it offers.
• The Four Game ModesMarathon, versus CPU, split-screen and online duels, and what each is actually for.
• Every Control in TETERIThe complete list for keyboard, touch and gamepad, including the ones that are not obvious.
• Playing on a PhoneTwo layouts, two control schemes, and the specific problems that had to be solved to make touch work properly.
• Playing Offline and Installing ItA service worker caches the whole game, so it runs with no connection and can be added to your home screen.
• How Online Duels WorkA room code, a direct browser-to-browser connection, and no account at either end.
• The CPU Opponent and Its Three DifficultiesHow the computer player decides where to put things, and what actually changes between rookie and nightmare.
• Every Setting and What It DoesVolumes, ghost piece, screen shake, scanlines and touch controls, plus which ones are worth changing.
• Accessibility in TETERIKeyboard navigation, screen reader announcements, reduced motion, and the honest limits of a canvas game.
• It Is Open Source, and What That Means HereMIT licensed, no dependencies at all, and a test suite you can run yourself.
• No Account, No Tracking, No CookiesWhat the game stores, what it does not, and why that is a deliberate position rather than an oversight.
• Reading Your Score and What Drives ItWhere the points actually come from in a real run, and which habits move the number most.
• The Look of the Game, and Why It Stays ReadableNeon and particle effects are only acceptable if the board stays legible underneath them.
• A Browser Game Versus an Installed OneThe honest trade-offs of playing in a tab rather than downloading something.

How TETERI is built

A browser game with no engine, no libraries and no asset files. How the rendering, the synthesised audio, the peer-to-peer netcode and the CPU opponent actually work.

• Building a Game With No Dependencies At AllNo engine, no framework, no library, no build step for the game itself. What that costs and what it buys.
• Rendering: Sprite Caches and Layer BakingDrawing four hundred glowing blocks per frame is slow. Drawing four hundred cached bitmaps is not.
• Every Sound Is Generated, Not RecordedOscillators, filtered noise and a reverb impulse built from decaying random numbers. No audio files anywhere.
• The Soundtrack Is a Sequencer, Not a FileA four-bar progression with drums, bass, arpeggio and a lead, whose tempo and arrangement climb with your level.
• Online Play With No Server At AllWebRTC connects the two browsers directly; a public relay handles only the introduction.
• Seeded Randomness: Why Both Players Get the Same PiecesA small deterministic generator, one shared number, and two identical bags on different machines.
• How the CPU Opponent SearchesEnumerate every placement, score the resulting board on four weighted features, take the best.
• Testing a Game Without Opening a BrowserKeeping the rules engine free of DOM references means the whole ruleset is testable from a terminal.
• One Layout Engine, Four ShapesSolo widescreen, solo portrait, split screen and a focus view, all produced by the same function.
• Telling a Flick From a DragTwo gestures that differ only in speed, and why measuring velocity at release is the only reliable answer.
• Making It Work Offline ProperlyCache the shell, revalidate in the background, and never serve a mix of old and new modules.
• Keeping Inside a Sixteen-Millisecond BudgetSixty frames a second means 16.7ms for everything. Here is where it goes and how it was measured.

Culture and science

The Tetris effect, the sleep-lab studies, the folk song everybody knows, and why a game about falling rectangles has outlived nearly everything released alongside it.

• The Tetris Effect: Seeing Blocks With Your Eyes ClosedPlay long enough and the shapes follow you into sleep. It has a name, a literature, and a fairly mundane explanation.
• The Research on Blocks and Intrusive MemoriesSeveral groups have tested whether playing a visuospatial game after a distressing event reduces later flashbacks. The findings are interesting and preliminary.
• The Song Everyone Associates With Falling BlocksA nineteenth-century Russian folk tune about a pedlar, and how it became the most recognisable video game music ever written.
• Why This Particular Puzzle Is So Hard to Put DownClear feedback, a failure you can always attribute to yourself, and no ending. A design that keeps offering one more attempt.
• Does Playing Improve Spatial Reasoning?Some evidence, some overstatement, and a reasonable position between the two.
• The Mathematics Behind the Seven ShapesWhy exactly seven, what happens with five squares, and the tiling problems that follow.
• Score Chasing, Speedrunning and Community RecordsA game with no ending produces a different competitive culture to one with a finish line.
• Falling Blocks as a Visual LanguageThe shapes became shorthand for computers, the eighties, and the idea of fitting things together.
• Puzzle Games and the Flow StateAbsorbed, time-distorted play requires difficulty to track ability closely. This genre does that automatically.
• Accessibility in Puzzle Games, and Where It Runs OutSome barriers in this genre are removable. One of them, so far, is not.
• Why the Simplest Games Outlive Everything Around ThemForty years of hardware generations have discarded nearly everything. A few rectangles survived all of them.
• The Genre Forty Years OnWhere falling-block games have ended up: competitive scenes, browser tabs, and a design nobody has improved.