How to play Gatelit: rules and how to read a circuit backwards
Everything you need to play Gatelit, plus tips to get a better score.
How to play
- Each switch on the left sends current down its wire when it's on (lever to the right, orange). Tap or click to flip it: moving switches is free.
- Light exactly the lamps the day asks for: the goal mark beside each lamp shows which must glow (a yellow dot) and which must stay dark (a crossed-out circle).
- The Goal strip above the board shows the same goal, lamps from top to bottom. There are 2 lamps on Monday and up to 5 on Sunday, and all must match at once.
- AND lights with both inputs on. OR lights with at least one. NOT (from Tuesday) flips its input. XOR (from Thursday) lights with exactly one.
- Tap or click a chip to see its card: every input case and what comes out.
- A solder dot means a wire branches: the same current feeds several gates or lamps. A wire can also run straight past a column to reach a gate or lamp further right.
- Wires that cross without a dot don't touch.
- Some gates read other gates: current always flows left to right, column after column. On Sundays every lamp sits behind two layers of gates.
- Flip the switches as much as you like, then press Power on: that spends one of your six tries. The current runs through the wires and every lamp lights or not.
- While you move switches the board stays dark: you have to work it out by reading the circuit.
- After each try, every lamp shows ✓ if it matches the goal or ✗ if it doesn't. Only one switch combination lights today's goal.
- Your tries are listed under the board: the switches you used, then each lamp lit or dark with its ✓ or ✗.
- A combination you've already tried can't be powered again: move a switch first.
- After six tries without the goal the day is lost and the board shows the combination that would have lit it.
- Your score is the number of tries: ⚡ 1/6 is perfect, X/6 means the lamps won the day.
- On a computer, keys 1–8 flip the switches, Enter powers on and Esc closes a chip's card. Sounds and vibration can be switched off in Settings.
- The week gets harder: Monday has 4 switches, 2 lamps and only AND and OR; NOT joins on Tuesday, XOR on Thursday; Sunday brings 8 switches, 5 lamps and two layers of gates before every lamp.
Strategy: start at the lamps, walk back to the switches
Don't guess from the left. Pick a lamp and ask what its gate needs. A lamp that must glow behind an AND tells you a lot: both of its wires must carry current. 💡 must glow ⬅ AND ⬅ both wires on
Some lamps speak loudest when they must stay dark. A dark OR means neither wire carries current, and a dark AND only means at least one is off. ⬛ must stay dark ⬅ OR ⬅ both wires off ⬛ must stay dark ⬅ AND ⬅ one wire off, or both
Keep walking back through each gate until you reach the switches. A NOT just swaps what you need: a wire that must be on before a NOT means the wire behind it must be off. 💡 ⬅ NOT ⬅ ⬛ off
XOR needs exactly one input on. On its own it never tells you which one, so come back to it once another lamp has settled one of its wires. 💡 ⬅ XOR ⬅ 🔌1 ✅ + 🔌2 ❌, or 🔌1 ❌ + 🔌2 ✅
Look for branching wires. A switch that feeds two lamps must please both at once: that is usually where the puzzle turns. Settle the sure lamps first, then use what you know to crack the tangled one.
Use your tries as experiments only when you're stuck. Each ✓ and ✗ tells you which lamps you already have right, so change as few switches as you can between tries.
Sharing shows each try as a row of lamps, 💡 lit or ⬛ dark, and ✅ when the whole goal lit up. It never shows your switches.