Pack Stack

How to Play

1. Tap a piece in the tray to select it. The first piece is selected automatically when a board opens.
2. Tap a suitcase cell to drop the active piece. The piece anchors at the tapped cell and extends to the right and down based on its current rotation.
3. Tap Rotate to spin the active piece by 90 degrees. Tap Undo to take the most recent placement back.
4. Pack every required piece before the per-board timer runs out. The board clears when every non-blocker cell is covered.
5. Use the keyboard if you prefer: every cell, tray slot, and action is a real button reachable by Tab and activated with Enter or Space.

Tips & Tricks

• Start with the larger pieces. They have fewer legal placements, so locking them in early simplifies the rest of the pack.
• Rotate before you commit. The Rotate button is free to press; only your final placement counts toward the rotation efficiency bonus.
• Watch the blocker squares. They split the suitcase into separate regions, so a piece that crosses the wrong blocker line cannot legally drop.
• Save Undo for the last two pieces. If your final piece does not fit, undo back to the spot where the gap appeared and try a different rotation for the prior piece.

Scoring

• Base clear: 100 points per board cleared.
• Rotation efficiency: up to 50 bonus points per board; one rotation per piece is free, each rotation past the baseline subtracts 5 points.
• Time bonus: up to 60 bonus points per board, decaying linearly to zero across a 90 second window from your first placement on the board.
• A failed (timer-expired or quit) board scores 0 and ends the run early; previously-cleared boards in the same run keep their score.

Daily and practice

• Daily: a deterministic three-board ladder picked by UTC date. Replaying the same daily does not extend your streak.
• Practice: a single random board from the same launch pack. Use it to warm up; it does not affect the streak.
• Streak: only a fresh UTC daily ladder clear bumps the streak counter; quitting a daily mid-run resets the streak to zero.

Privacy

• Pack Stack does not send any of your moves off device. Telemetry events carry only derived numbers (total score, mode, boards cleared).
• The recap summary uses your scoring numbers only; the board layouts and piece definitions are bundled with the game and never carry personal data.
• Daily completion, current streak, and high score are stored in browser local storage on your device only. Clearing site data resets them.

Use cases*

• Daily spatial break: three short boards fit comfortably in a coffee queue.
• Spatial reasoning warm-up: rotating and fitting parcels builds a small habit of plan-before-place.
• Friendly competition: every player sees the same daily ladder, so scores compare cleanly.
• Mobile-friendly play: the grid and tray reflow to small screens and only need taps.

*Pack Stack is an entertainment game and not a cognitive training tool. Use case suggestions are for casual play only.

How do I play Pack Stack?

Rotate parcel pieces and pack them into the suitcase before time runs out.

Is Pack Stack free to play?

Pack Stack is free to play on STS Games in any modern web browser.

What kind of game is Pack Stack?

Pack Stack is a puzzle game designed for quick, replayable sessions.