Regional Akari: Light Up with courtyards
Regional Akari is a variant of the Light Up (Akari) logic puzzle. The numbered walls of the classic puzzle are replaced by coloured regions, which Nightwatch calls courtyards, and each courtyard must hold exactly one lantern. Nightwatch is a nightly Regional Akari game for Android, with a new board every night.
How it differs from classic Light Up
| Classic Light Up | Regional Akari (Nightwatch) | |
|---|---|---|
| What you place | Light bulbs | Lanterns |
| The clues | Numbers on some black walls: how many bulbs touch that wall | Coloured courtyards: each one needs exactly one lantern |
| What stops light | Walls | Walls only; a courtyard edge does not |
| Two lights in one line of sight | Not allowed | Not allowed |
| Every white square | Must end up lit | Must end up lit |
The courtyards change how the puzzle feels. In classic Light Up the clues sit on the walls and you reason outward from them. In Regional Akari every courtyard is a clue at once, and because light crosses courtyard edges, one lantern can settle squares in several courtyards.
The rules, as Nightwatch writes them
- Every courtyard gets exactly one lantern.
- A lantern lights its own square and shines along its row and column until a wall stops it. A courtyard edge does not stop light, and a lantern set on a lit square is dazzled, which is never allowed.
- No lantern may shine on another lantern.
- Every open square must end up lit.
How every board is checked
A board is fair only if it has one answer and you can reach that answer by reasoning. For this page we ran every board in Nightwatch through the game's own solver, the same code the app's hints come from. It has two parts:
- a referee that searches every board exhaustively and stops counting at two solutions. Every board must stop at one;
- a solver limited to six named deductions, the ones a person makes (how to solve Light Up). Every board must be finished by those deductions alone, without a guess.
All 1,651 boards pass both: the 70 campaign rounds, the 731 nightly boards made so far and the 850 free-play boards.
The numbers
What the 731 nightly boards look like, measured on 11 October 2026:
- Courtyards per board: from 5 to 17, with a median of 7.
- About 16.9% of the squares are walls, and 12.7% of the courtyards are a single square, which is a free lantern.
- The hardest deduction each board needs: a square already lit on 114 boards, a courtyard that alone reaches a dark square on 210, a square that would leave another dark on 204, and a boxed-in neighbour on 203.
| Size | Courtyards (median) | Solving steps, median (range) | Squares that are wall |
|---|---|---|---|
| 5×5 | 5 | 21 (19–22) | 19.4% |
| 6×6 | 6 | 24 (20–29) | 20.1% |
| 7×7 | 6 | 26 (14–44) | 15% |
| 8×8 | 8 | 35 (18–56) | 17.6% |
| 9×9 | 10 | 48 (23–71) | 15.9% |
The nightly boards already made run from 1 September 2026 to 31 August 2028.
Nightwatch
Nightwatch plays Regional Akari rather than the numbered-wall puzzle: courtyards in place of numbers, a new board every night, seventy campaign rounds in five districts, and hints that teach the deductions before they give anything away. It is free on Android, plays offline, and has no account. You can play tonight's board in your browser on our home page.
Questions
What is Regional Akari?
Regional Akari is a Light Up variant in which the open squares are divided into regions, and each region must hold exactly one light. The other rules stay: light runs along rows and columns until a wall stops it, no light may shine on another, and every square must end up lit.
Where do Nightwatch's boards come from?
Nightwatch's boards come from Brightloop Studios and are checked by the game's own solver.
Is there a Regional Akari app?
Yes. Nightwatch is a nightly Regional Akari game for Android by Brightloop Studios. It is free, plays offline, and has a new board every night. You can also play tonight's board in your browser.
How do you know every board has one answer?
We count. The game's referee searches every board exhaustively and stops at two solutions; all 1,651 boards stop at one. A second solver, limited to six deductions a person can make, finishes every one of them without a guess.
Nightwatch is on Android. On iPhone, play tonight's board here.
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