How to Play

What you're playing

What sets it apart:

• 1v1 battles where lines you clear send garbage rows to your opponent.
• XNT-staked matches where both players deposit, winner takes the pot.
• TETRIS reward token (Token-2022 on X1) paid out at match end, proportional to score.
• Spectator + replay views — any match is watchable live or scrubbable after.

Modes

Match codes are 5-char Crockford base32 — no ambiguous characters (0/1/I/L/O/U). 33M possible codes.

Controls

On-screen buttons exist for touch devices but work in any browser. Keyboard input is debounced 70 ms so a held key doesn't fire faster than the engine ticks.

Solo play

Pieces and the 7-bag

Standard tetrominoes (I, O, T, J, L, S, Z) drawn from a 7-bag shuffler. Every 7 consecutive pieces contain exactly one of each, in a random order. You'll never see a long S/Z drought or an I-piece famine longer than 13 pieces apart.

NEXT and HELD

• NEXT shows the upcoming 4 pieces stacked vertically. Plan two or three moves ahead.
• HELD stores one piece on demand. Press H to swap the active piece into the slot. Limit: one swap per spawned piece — resets when you lock.

Scoring

Per-lock score:

final = base * current_level + combo * 50

Combo increments on every consecutive line-clearing lock; resets to 0 on a non-clearing lock. Level rises by 1 every 10 lines, capped at 15. Each level shortens the auto-fall interval (800 ms at L1 down to 20 ms at L15).

Audio

All sounds are synthesized in-browser via Web Audio — no audio files to download.

• Music: Korobeiniki melody + bass loop. Persists across reloads via localStorage.tetrisMusic.
• SFX: move, rotate, drop, clear, tetris, levelup, hold, garbage, gameover.

Battle mode

How to start a match

1. Open queue. On battle.html click FIND MATCH. The server pairs the two longest-waiting wallets; both clients navigate to the same match.html session — one as p1, the other as p2.
2. Invite. On battle.html click CREATE. You get a 5-char code and a shareable link. Send it; whoever opens that URL becomes p2.

Match lifecycle

free:   create -> lobby -> playing -> finished / abandoned
staked: create -> awaiting_deposit -> lobby
              -> (p2 joins) awaiting_deposit -> playing
              -> finished / abandoned

Each player gets their own piece sequence

Both players use the 7-bag distribution, but their seeds differ — and each player's seed is only sent to that player, never to the opponent or any spectator. Shared-seed mode was tried first and discarded — it created compounding bad luck (both stuck in S/Z droughts together) and let players predict each other's queue.

Garbage rows — the core battle mechanic

When you clear lines, the surplus is sent to your opponent as gray rows with one random hole column. They push the opponent's stack up; if any of their blocks get pushed off the top of the playfield, they top out and lose.

Damage table

Singles are free score but zero damage. The whole game pressures you toward setting up tetrises.

The offset rule

Incoming garbage doesn't apply instantly — it sits in a queue. Your own clears cancel pending incoming garbage before sending any out:

You have 3 incoming garbage queued.
You clear a tetris (would send 4).
  -> 3 cancel against your own queue (queue now 0).
  -> 1 surplus is sent to opponent.

This is what makes Tetris-vs-Tetris feel back-and-forth: a fast counter completely neutralizes an incoming attack and still hits back with leftover damage.

When garbage actually lands

Defensive mode

Tap DEF (or press D) to enter defensive mode. The button glows green; a DEF chip appears next to your handle (and opponents see it too).

While defensive:

• You send no garbage on clears.
• Each successful clear removes 1 existing junk row from the bottom of your board (cap: 1 per clear).
• Your incoming queue is not cancelled by your clears — pending garbage still threatens you.

A JUNK -1 banner flashes on each junk-row removal. If your stack is clean (no junk), defensive clears nothing extra.

Match end

• Topout — your stack gets pushed off the top of the playfield. Opponent wins. Match auto-finishes; result broadcast to everyone watching.
• Forfeit — reload or close the tab. The browser fires a sendBeacon to /forfeit as it unloads; opponent wins.
• Time limit — if the match was created with a time limit, the server auto-finishes at started_at + time_limit_ms; higher score wins, equal = draw.
• Abandonment — server-side sweep marks a match abandoned if there's been no activity for 2 minutes, or 30 minutes total. The still-alive (or higher-scoring) player gets the win.

XNT stakes

A staked battle puts XNT (X1 mainnet native token) into escrow from both players. Winner takes the full pot (2× stake).

Custody model

A single server-controlled keypair holds in-flight stakes. Its public key is logged on the server and shown in match snapshots so clients know where to deposit.

Lifecycle

Unit: lamports (1 lamport = 10⁻⁹ XNT). UI accepts decimal XNT and converts.
Per-match cap: 100 XNT.

Why deposits use the master wallet (popup)

The session keypair is derivable from one master signature and lives in browser sessionStorage. That's fine for signing high-rate game events. It is not suitable for moving real money. So deposits use the master wallet — you explicitly approve each fund movement in your wallet's popup.

Orphan deposits

If a client signs a deposit but the /confirm-deposit POST never lands (tab closed, network blip), funds hit escrow with nothing crediting them. A reconciliation sweep runs every 5 minutes:

1. Fetches the last ~200 inbound escrow signatures from X1.
2. Skips any already credited to a match.
3. Records new ones as pending in the escrow_orphans table.
4. Refunds anything still pending after a 10-minute grace window, back to the original sender.

Safety caps: max 5 refunds per sweep, 20 per rolling hour.

TETRIS reward token

When the server has TETRIS_REWARD_MINT configured, match results distribute a Token-2022 SPL reward (symbol TETRIS, 6 decimals) to both players, proportional to their score (1 TETRIS per point at current K). The amount per slot is recorded on the match row and visible in your wallet panel + the match result overlay.

Spectating

Anyone can open watch.html?code=XXXXX for any match — live or finished. No wallet needed. Read-only view of both boards side-by-side, with score/lines/level for each, plus DOUBLE/TRIPLE/TETRIS banners on clears and garbage-incoming banners. Spectators also hear SFX for both sides.

Wallet & session keys

A wallet has two parts:

• Master — your real wallet (Phantom / Backpack / X1 / Manaswap). Used for deposits and one signature derivation.
• Session — long-lived keypair derived from one signature, used to silently sign per-frame game events.

Derivation

master.signMessage("tetris-v0.1")  ->  64-byte signature
session_seed    = signature[0..32]
session_keypair = Ed25519.fromSeed(session_seed)

Same master + same message = same session keypair, every device, every browser. Reproducible.

Why two keys

Game actions (score posts, state pushes, line-clear claims) happen many times per second. Showing a wallet popup for each one is unworkable. So we sign once with the master to derive the session key, then use the session for all subsequent silent signing.

Strategy notes