NIGHTWATCH: hold the keep till dawn
The Heart of the keep sits in the middle of a nine-by-nine yard. Each night a handful of creatures come in from the edges, and every creature follows a rule written out in plain words on its card. Nothing is random once the night begins. Your job, before you press Hold the night, is to predict where each creature will stand on each of twelve turns and to place your walls, pits, lanterns and decoys so that none of them reaches the Heart. Then you watch the night play out exactly as the rules said it would. Score is the number of nights you hold.
The shape of a run
- A night is twelve turns. Each turn every creature acts once, in the order listed: A, then B, and so on. Order matters for mimics.
- If a creature steps onto the Heart, the keep falls and the run ends.
- Creatures still outside at dawn slink away. Each new night brings more of them and new kinds.
- Before each night you receive new pieces. Unused pieces stay in your bank, so saving is a real option.
- Nothing can be built on the Heart or the four tiles touching it. The courtyard stays open.
The pieces
| Piece | What it does | Lasts |
|---|---|---|
| Wall | Nothing walks through it. Breakers smash it instead of going around. | Three nights, then crumbles at dawn |
| Pit | Swallows the first creature that steps in. | Until used |
| Lantern | Blocks like a wall and lights the eight tiles around it. Moths fly to it; dusk creatures refuse the light. | Four nights |
| Decoy | A straw dummy. Heart-seekers go for it when it is closer than the Heart; the first to reach it tears it apart. | Until torn apart |
How creatures move
Every creature has a kind, a pace and sometimes a quirk, and its card spells out all three.
- Seekers walk toward the Heart, or toward a decoy if one is closer. Each step they pick the direction that closes the larger gap. If that step is blocked they try the other useful direction; if both are blocked they stand still.
- Flankers do the same but always try east or west first while that still helps, then north or south.
- Chargers keep going in a straight line. When blocked they turn clockwise (north, east, south, west) and carry on.
- Moths fly to the nearest lantern and stop beside it, dazzled for the rest of the night. With no lantern on the board they behave as seekers.
- Mimics repeat the last step of the creature listed just before them. If that step is blocked they stand still; if the creature before them did not move this turn, they walk toward the Heart.
- Pace. Most creatures take one step per turn. Some move only on even turns. Some take two steps every turn.
- Quirks. Dusk creatures never enter lantern light. Breakers smash the first wall in their way, which uses up that step.
- The tie-break. When a creature is exactly as far across as it is up or down, it moves up or down first. Creatures never block each other; two can share a tile.
A worked prediction
A seeker starts at the west edge, three rows above the Heart's row and four columns to its left. The larger gap is horizontal, so its first step is east. Now it is three up and three across: a tie, so it moves down (vertical first). Two up, three across: east. Two up, two across: down. One up, two across: east. One up, one across: down. It is now in the Heart's row, one tile away, and the next step takes the Heart on turn seven. Any single wall on that zigzag path forces a detour that costs a turn, and the detour itself is predictable by the same rule: blocked east, it tries down instead. Walk it on the board before you place anything; the game will do exactly this.
Strategy
- Predict before you place. Walk each creature in your head one turn at a time. The rules never bend, so a correct prediction is a correct plan.
- One wall stops a one-direction creature. A creature coming straight along a row or column is stopped dead by a single wall. One coming on the diagonal needs both of its useful directions closed, or a pit.
- Pits are investments. Walls crumble, pits do not. A pit on a lane that creatures use every night keeps paying.
- Lanterns do two jobs. They are bait for moths and a fence for dusk creatures, and they block like a wall besides.
- Let chargers wander. Their paths loop around the yard and often never cross the courtyard. Spend your pieces on the seekers.
- Watch the order. A mimic copies the creature above it on the list. Stop that creature and you have usually stopped the mimic too.
Every night can be held
Before a night is dealt, the generator rolls a set of creatures and runs a bounded solver that tries to hold the night with the pieces actually in your bank. If the solver cannot find a plan, the night is re-rolled. Only when a plan exists is the night shown to you. The Hint button places one piece from such a plan and is counted on your record. The solver is deliberately bounded (it searches plans of up to four pieces), so late nights are hard but never impossible: a run ends when the generator cannot produce a holdable night within its attempts, which for a perfect planner happens after roughly seven to twenty nights, eleven in a typical run. Nobody has an infinite run, and that is by design.
Tonight's watch and endless
Tonight's watch is the same keep and the same creatures for everyone, changes at midnight UTC, and can be played once a day. Endless starts a fresh keep whenever you like. Both record your best, and the share text shows your nights as a row of moons without revealing the plan.
Questions people ask
Why did a creature walk around my wall?
Seekers try the other useful direction when blocked. If both directions help them, one wall only redirects; close the second direction or use a pit.
Do creatures attack my pieces?
Only breakers, and only walls. Pits, lanterns and decoys are not attacked, though a decoy is destroyed by the first creature to reach it.
Can I undo a placement?
Yes, any number of times until you press Hold the night.