Start with First circle
On a new journey, choose "Let’s make a spark". The optional voiced tutorial finishes with "Build my first circuit"; the written instructions work without sound. Your first mission is "First circle", with the goal "Wake one house". The battery and bulb are already on the workbench.
- Connect the battery’s + terminal to terminal A on the bulb.
- Connect terminal B on the bulb back to the battery’s − terminal.
- Watch the bulb and mission feedback. The circuit responds as you build; this first activity does not require a Play button.
Make connections you can explain
Drag from one copper terminal to another, or tap a terminal and then its partner. If the targets are awkward, use Wire, the control named "Connect named terminals", to choose the two ends by name. Tapping the body of a part does not complete a wire.
A single connection leaves the return path open. A wire directly from battery + to battery − bypasses the bulb. Trace the whole path through the bulb before adding more wires. Try removing one connection, predict the result, and reconnect it.
Repair a circuit without starting over
Use Undo and Redo to compare changes. Select an unwanted wire and choose "Snip wire". Measure helps inspect electrical values; Diagram shows another view of the current circuit. Later missions introduce different components, so follow that mission’s terminal names and success criteria rather than repeating the first solution.
Read the star criteria on the mission panel and reward screen. Completing the basic goal and earning every optional star are separate targets.
Keep these controls nearby.
| Control | What it does |
|---|---|
| Copper terminals | Drag between two terminals, or tap the first and then the second. A part’s body is not a wire endpoint. |
| Wire | Choose named terminals when the small connection targets are difficult to reach. |
| Undo / Redo | Compare the circuit before and after a change. |
| Snip wire | Select a wire, then remove that connection. |
| Measure / Diagram | Inspect electrical feedback or another representation of the current circuit. |
When the next step is unclear.
- The bulb stays dark.
- Trace the return path from the bulb to battery −. One wire from the battery to the bulb is only half of this circuit.
- A wire seems attached but nothing changes.
- Check that its endpoint reaches a copper terminal. Use Wire to choose the endpoints by their names.
- The battery is connected directly to itself.
- That bypasses the intended bulb. Snip the bypass, then trace a path through the bulb.
- A later diode still blocks the path after turning it.
- Turning the drawing does not exchange terminal identities. Follow that mission’s named terminals and reconnect the wires as instructed.
ONE THING TO TRY
Predict an open circuit.
Once the first bulb is lit, predict what will happen if you remove just its return wire. Snip that connection, look at the feedback, then use Undo. Explain why the two states differ using the path through the bulb, rather than the shape of the wires.
Can you point to the exact gap that stops the conducting path?
Keep your discoveries
Progress is saved in this browser. In Builds & backups, "Export invention" saves an individual construction; the "Back up your whole journey" area covers the wider journey. Keep an exported copy before clearing browser storage or moving devices. A normal local save is not a promise of cross-device recovery.
Use these ideas with the game’s simulated parts. Household electrical wiring is not an appropriate experiment.
For account return access, read the player privacy notice. An account and a browser-local game save have different recovery limits.
For playing together.
PUT THE IDEA INTO PLAY
A light starts with a complete path.
Take one prediction into the game, then explain what changed.
Bonus levels: Lighthouse Relay
Wire the lamps and restore three signals without connecting the battery directly across a wire. Play the bonus levels ↗