# TGL Stack Rush

> A free, no-install, browser-based single-tap stacker. A block sweeps
> left↔right across the stage; tap to drop it on the tower below. Overhang
> is sliced off; perfect drops keep your full width and chain into combos
> (×1/×2/×3/×5 at 1-2/3-4/5-7/8+ consecutive perfects). Integer-only
> geometry, server-validated replay scoring, global leaderboard.

Tagline: Build High. Stay Tight. Go Far.

Site: https://tglgames.com/
Play: https://tglgames.com/stack-rush/
About: https://tglgames.com/stack-rush/about/
Leaderboard: https://tglgames.com/api/leaders?game=stack-rush

## What it is

Stack Rush is a single-page browser take on the classic tap-to-drop
stacker (Ketchapp Stack, Stacky, Stack Tower, Block Tower, etc.). One
input, one rule, infinite skill ceiling. Free, no signup, no install,
no ads, no in-app purchases. Plays on every modern browser — desktop,
tablet, phone, foldable.

## Rules

- A block sweeps left↔right across a fixed-width stage. Speed scales
  with level (level 1 = slow, level 20 = insane).
- Tap (mobile), click (desktop), or press Space / Enter to drop the
  block.
- The block lands on the tower. Whatever overlaps the previous block's
  footprint stays — the rest is sliced off and tumbles away.
- The next block enters with the new, smaller width.
- Miss the tower entirely (overlap below `MIN_OVERLAP`) and the run
  ends.

## Scoring

- `+10` base points per successful drop.
- `+25` bonus on a *perfect* drop (within `PERFECT_TOL` of the previous
  block's center). A perfect drop keeps the full previous width.
- Both numbers above are multiplied by the current combo multiplier:

  | Combo length | Multiplier |
  | -----------: | ---------: |
  |          1–2 |        ×1  |
  |          3–4 |        ×2  |
  |          5–7 |        ×3  |
  |           8+ |        ×5  |

- `+50` height bonus every `LEVEL_EVERY` (10) successful drops. Level
  increments at the same boundary.
- Game over: `overlap < MIN_OVERLAP` (the block misses the tower).
  The missed block is not scored.

## Constants (must match `/api/games/stack-rush.php`)

| Constant       | Value | Meaning                              |
| -------------- | ----: | ------------------------------------ |
| `STAGE_W`      | 1000  | logical width of the play area       |
| `BASE_W`       |  550  | first (base) block width             |
| `MIN_OVERLAP`  |   50  | run ends below this overlap          |
| `PERFECT_TOL`  |   30  | within this of prev center = perfect |
| `BASE_PTS`     |   10  | base per drop                        |
| `PERFECT_BONUS`|   25  | added on perfect (before mult)       |
| `HEIGHT_BONUS` |   50  | every `LEVEL_EVERY` drops            |
| `LEVEL_EVERY`  |   10  | drops per level                      |
| `MAX_BLOCKS`   | 5000  | hard cap                             |
| `MAX_SCORE`    | 5e6   | sanity ceiling                       |

Geometry is integer-only end-to-end so server replay is bit-for-bit
identical to the client run.

## Move log

```json
[
  { "t": 217,  "x": 500, "perfect": 1 },
  { "t": 503,  "x": 502, "perfect": 1 },
  { "t": 791,  "x": 540, "perfect": 0 },
  { "t": 1080, "x": 50,  "perfect": 0 }
]
```

- `t` — ms since `/api/run/start`.
- `x` — integer center of the dropped block at release, in `[0, STAGE_W]`.
- `perfect` — 1 if `|x − prev_center| ≤ PERFECT_TOL`, else 0.

## Determinism + replay

- `/api/games/stack-rush.php :: StackRushValidator::validate($moves, $seed)`
  walks the log and recomputes overlap, slice, perfect detection,
  combo, multiplier, height bonus, and level — entirely with
  `intdiv()` and integer compares.
- Score must match exactly. Client-server mismatch →
  `validated='pending'` for review (not silently accepted).
- Mulberry32 PRNG (shared `Rng` class) is included for parity with
  other games even though Stack Rush v1 doesn't consume it for level
  randomness.

## Anti-cheat

- HMAC-signed run tokens; single-use, tied to a server-issued seed.
- Server replays the full move log; client score is overridden by the
  recomputed value.
- Score bounds: `[0, 5,000,000]`.
- `duration_ms` is bounded against the server-issued `/api/run/start`
  wall time (±10 s slop).
- Per-run row in `stack_rush_runs` (1:1 with `runs`) records:
  `blocks_placed`, `highest_stack`, `perfect_drops`, `longest_combo`,
  `level_reached`, `death_reason ∈ {miss, cap, invalid}`,
  `input_key/pointer/dpad`, `move_log`.

## Controls

- **Tap** the stage (mobile / tablet).
- **Click** the stage (desktop).
- **Keyboard**: `Space` or `Enter`.

Each input source (`pointer` / `key` / `dpad`) is tracked separately
for stats.

## Privacy / signup

- No account required. Guests get an auto-generated username on first
  visit; rename anytime.
- No tracking pixels, no analytics SDK, no third-party scripts.
- Raw IP, user-agent, and full request bodies are logged for
  ops/security review (project-wide stance) — never sold or shared.

## Genre / keywords

stack rush, stacker, tower stacker, tap to drop, block stacker,
single-tap arcade, browser stacker, free stacker, html5 stacker,
online stacker, no install stacker, mobile stacker, perfect drop combo,
leaderboard stacker, replay-validated stacker, deterministic stacker,
mgwalk, tglgames.com

## Other games on tglgames.com

- Snake · /snake/
- 2048 · /2048/
- Brick Blaster · /brickblaster/
- Space Drifter · /spacedrifter/
- Pool · /pool/
- Last Card Standing · /last-card-standing/
- Blackjack · /blackjack/
- Poker · /poker/
- Euchre · /euchre/

## Author

mgwalk — https://tglgames.com/