Gatelit (Dayzle)

About Gatelit (Dayzle)

Gatelit is one of the daily games on Dayzle, a site of original puzzles by TLL Studios. Each day brings a green circuit board, the same for everyone: a column of switches on the left, gates in the middle and lamps on the right. A goal strip says which lamps must glow and which must stay dark, and all of them have to match at once.

The gates follow simple rules. AND lights only when both of its wires bring current, OR when at least one does, NOT turns no current into current, and XOR lights when exactly one wire brings current. A solder dot means a wire splits to feed several gates, and some gates read other gates, so current flows left to right column by column. Tapping a chip shows a card with every case.

Flipping switches is free, but the board stays dark while you do it, so you have to reason the answer out. Pressing Power on spends one of six tries, and each lamp then shows whether it matches the goal. A combination you have already tried cannot be powered again, and only one combination lights the day's goal. Your score is the number of tries, with one being perfect.

The week gets harder in steps. Monday has four switches, two lamps and only AND and OR gates; NOT joins on Tuesday and XOR on Thursday; Sunday has eight switches, five lamps and two layers of gates before every lamp. Past days can be played from the archive without counting towards your stats.

How to play Gatelit (Dayzle)

1. Open Gatelit on dayzle.app and read the goal: a yellow dot means a lamp must glow, a crossed circle means it must stay dark.
2. Follow each lamp's wire back through its gates to work out which switches must be on or off.
3. Tap the switches to set them; moving them costs nothing.
4. Press Power on to spend a try and see a tick or cross next to each lamp.
5. Light every goal lamp within six tries, then share your rows of lit and dark lamps.

Screenshots

Tips

• Start at the lamps and walk back: a lamp that must glow behind an AND needs both wires on, a dark OR needs both wires off.
• Settle the lamp that tells you most first, since a switch that feeds two lamps has to please both.
• An XOR alone never says which wire is on; come back to it once another lamp has fixed one of its inputs.
• If you must experiment, change as few switches as possible between tries so the ticks and crosses stay readable.

Questions