Aboard the ship the pack lies open: a grid eight squares wide and five tall. Everything you own is a shape made of squares, and you place each one by hand. The left of the grid glows. That lit block is the harness, the only place a part does anything.

You turn the Threat Sensor until the little arrow on its foot presses against the side of the Pulse Projector. A seam lights between them: the rig will now shoot on its own. The Manual Trigger's arrow touches the Barrier Plate: one button, one shield. A tall oxygen canister stands in the dark squares on the right. Sixteen squares are still empty, and you leave them empty on purpose.

In Cargo Turn the Fork Relay sits in its cradle, a T of four squares. It drops into the gap beside the canister. Two rooms later the isolation bridge comes free: a single bar eight squares long. It only fits if one whole row is clear. It is, because you kept it clear. Had you brought a second canister, the bridge would not fit at all until something went on the floor.

Back aboard, with no clock running, you pull the Manual Trigger out of the glow and turn the Fork so that the Sensor feeds its stem and its two arms touch the Projector and the Barrier. Three seams light. The same parts, a different machine, and you can see why at a glance.

| | |

|---|---|

| **Decided by the owner** | The inventory is a grid. Items have shapes. It should feel like Backpack Hero: you arrange things by hand and the arrangement matters. |

| **Already decided earlier, kept** | Equipment, spare oxygen and loot compete for the same space. Everything carried comes home on death. Nothing is ever discarded for you. The journal fully pauses the game. |

| **Proposed on this page** | The grid size, every shape, the lit block, links made by touching, the floor strip, when the pack may be opened, and how it looks. |

**1. The pack is one grid.** Eight wide, five tall, forty squares. One old "carrying unit" equals four squares, so every earlier example in the wiki still adds up: ten units were forty squares, a one-unit part is four squares, a two-unit canister is eight.

| Item | Squares | Shape |

|---|---:|---|

| Threat Sensor | 4 | an L: a stalk of three with a foot |

| Pulse Projector | 4 | a straight bar of four, the barrel |

| Manual Trigger | 4 | a two by two box |

| Barrier Plate | 4 | a J, the mirror of the L |

| Fork Relay | 4 | a T: a stem and two arms |

| Impact Dynamo | 4 | an S |

| Capacitor | 4 | a two by two box |

| Arc Emitter | 8 | a fat U |

| Oxygen canister | 8 | two wide, four tall |

| Isolation bridge | 8 | one bar, eight long |

| Navigation coupler, regulator core | 8 | awkward on purpose: an L of five with a block of three |

| Scrap and other loot | 1 to 6 | irregular; loot is where the awkward shapes live |

**3. Shapes turn, they do not flip.** Quarter turns only. No overlapping. A shape must lie wholly inside the grid. That is why the L and the J are different items.

**4. The lit block is the harness.** At the start it is four rows by five columns at the left of the grid, twenty squares. A part works only when every one of its squares is lit. Anything may lie on lit squares, but only parts use them, so a canister parked in the glow is wasted glow. The bottom row is never lit: it is the cargo shelf, and it is where a long bar rides. Installing the navigation coupler aboard lights two more columns. Installing the second ship assembly lights the last one.

**5. Parts link by touching.** Each part that sends something has one small arrow on one edge. If that arrow presses against a part that can accept what it sends, a seam lights between them and they are linked. The receiving part accepts on any edge. One arrow touches exactly one square, so a link is never ambiguous. The Fork Relay takes its input anywhere on its stem and has an arrow at the end of each arm. The ship's power number stays: if the lit seams ask for more power than the ship supplies, the newest seam stays dark and says why.

This replaces the journal's link editor. The journal keeps a read-only page that explains, in words, what the current arrangement does.

**6. The floor strip.** Beside the grid is a strip showing whatever lies within the astronaut's reach: things you put down, a part sitting in a cradle, a canister on a shelf. Drag from the pack to the strip to put something down. Drag from the strip into the pack to pick it up. If a find does not fit, you rearrange, or you leave something on the floor, or you leave the find. A thing on the floor stays in that room until you come back for it.

**7. Canisters.** A canister is coupled by clicking its valve in the pack. It then feeds the suit while you move, exactly as now. Its position in the grid does not matter.

**8. Station machines.** Seating the Fork in the service board, freeing the bridge and handing air to a survivor stay as timed work at the fixture. The object leaves or enters the grid when the work completes. Work that ends with an object entering the pack checks first that a place for its shape exists, and refuses before any time is spent.

**9. Death and return.** Everything in the grid comes home, in the same arrangement.

This is the biggest open choice. Aboard the ship it is always free. In the station there are three options.

- **A. Paused plan, live hands.** Opening the pack pauses the world, like the journal. You rearrange freely. When you close it, each part that entered or left the lit block costs a few live seconds of standing still, and walking away cancels the change. Shuffling cargo is free. This keeps the owner's full pause for thinking and keeps re-rigging under fire a real risk. It is what I recommend.

- **B. Fully paused.** Open, rearrange, close, no cost. Simplest and closest to Backpack Hero. Re-rigging in the middle of a horde becomes free.

- **C. Fully live.** The world never pauses while you drag. Tense, but fiddly with a crowd on you.

- The grid sits left of centre at a size where one square is about a thumbnail. The floor strip is on its right. The lit block glows softly; the cargo squares are dark metal.

- Each item is drawn as its object, filling its squares, tinted by kind: parts, air, objectives, loot.

- Arrows are small bright chevrons on the edge of the part. A lit seam is a bright line along the shared edge, with a short label on hover: "Sensor triggers Projector".

- Dragging shows a ghost: green where it fits, red where it does not. Right click or R turns the held item. Releasing over a red spot returns the item to where it came from.

- Hovering an item shows a small card: its name, what it does in one sentence, what its arrow sends and what it accepts.

- Beside the grid: squares used and free, power drawn against the ship's supply, and the suit's air.

- In the station the HUD shows a thumbnail of the pack, so the player always sees how full it is without opening it.

- **Survival And Loadout**, "What the astronaut can carry and use": carrying units become squares, the rig area becomes the lit block.

- **Player Information And Options**, "Manifest and property": the four text sections become the grid, the floor strip, and a list of things left elsewhere.

- **Build Rules** and **Equipment Catalogue**: costs written as units convert at four squares a unit. "Links are edited in the journal" becomes "links are made by touching".

- In the game as built today: the text pack panel on the I key, the ship's manifest list, and the journal's link editor.

I tested these shapes by brute force before writing them down.

- The four starting parts fit the lit block with both links made, in eight different arrangements.

- The Fork rig, Sensor into Fork into Projector and Barrier, also fits the lit block, in twenty arrangements.

- Five four-square parts can never all be lit at once while one of them is the T-shaped Fork. A T covers three squares of one checkerboard colour and one of the other, and twenty lit squares cannot absorb that. So the old limit of four working parts survives as geometry, not as a rule.

- The opening rig, one canister, the Fork and the bridge all fit together. With two canisters the bridge does not fit until something goes on the floor. That is harsher than the old example, where it still fitted, and is easy to tune by moving an arrow.

1. **When can the pack be opened in the station?** A, B or C above.

2. **Links by touching.** Should this replace the journal's link editor entirely? If two parts that do not touch must sometimes be linked, a small "conduit" piece could carry a link across a gap.

3. **Does the pack itself grow?** Here the grid stays eight by five and only the lit block grows. Backpack Hero grows the bag. Which do you want?

4. **Does position matter beyond links?** Backpack Hero has rules like "works better in the top row" or "stronger next to armour". Wanted here, or is touching enough?

5. **Turn only, or turn and flip?**

6. **Is four squares per part the right grain?** Bigger, stranger parts make harder puzzles and fewer parts per rig.

7. **What is drawn in each square?** The kit has no icons for these objects. Free art would have to be found, or the objects drawn as simple silhouettes.