How to play
You are defending Earth from an alien attack. One of 205 real cities is the target, and that target stays the same throughout your mission. Find it by combining six messages.
The six-round mission
- Read the transmission. Start with a five-degree Celsius band for the target’s typical temperature in the current calendar month. The °F / miles control converts the clues if you prefer.
- Deploy ten shields. Select a numbered shield and click or tap the map. You may place fields between cities. A field can protect several nearby city markers.
- Commit your defense. Place every available shield before selecting Commit defense. If the hidden city lies outside all fields, the mission ends.
- Combine the evidence. If you survive, read the next message. Reposition the remaining shields around cities that fit all the clues. The available shield counts are 10 → 8 → 6 → 4 → 2 → 1.
- Choose the exact city. Round six replaces area placement with city selection. Click or tap a city’s circular button, or search for it and choose it. Confirm your answer to finish.
Desktop, touch and keyboard controls
- Mouse or touch: click or tap to place; drag a shield to reposition it; drag the ocean to pan. Pinch with two fingers or use + and − to zoom; use Fit map to reset. Mouse wheels also zoom.
- Search: enter a city or country, choose a result, then use Place selected shield. Search locates a city but does not reveal its clue measurements.
- Keyboard: use Tab to reach controls and city markers, Enter or Space to activate them, and the zoom buttons to inspect the map. Search is an alternative to precise map pointing.
- Small screens: read the transmission above the map, then scroll to the shield rack. You can scroll the page outside the map; dragging inside the map pans it.
What the effects tell you
Real and decoy impacts look alike. Survival only tells you that some shield covered the target. Dashed gray fields show shields removed at the previous transition: they no longer protect anything. Toggle Show previous positions to hide them.
Think before you commit
There is no placement timer. Keep earlier messages in mind, use the transmission archive, and spread shields over distinct candidate regions rather than piling them on one guess. All shields must be deployed, even when you think you already know the city.
A mission ends with the target city and its full clue solution. Use New mission to try another target. Closing or reloading the page clears the current mission.