Power Grid
A gold power plant sits somewhere on the board, and a handful of buildings need to be connected to it — but you only have enough wire for a fraction of the empty cells between them. Tap a cell to lay a wire, tap a wire to pull it back up, and watch the whole network glow green the instant current can actually flow from the plant to a building.
Every stage is solvable with wire to spare if you route efficiently. The challenge is resisting the urge to build three separate direct lines when one shared trunk with short branches would get every building powered for less.
How to Play
- Tap an empty cell adjacent to your growing network to extend it with a wire
- Tap a placed wire to remove it and get that wire back in your budget
- The gold circle is the power plant — it's always live and can't be removed
- Square tiles are buildings — they turn green the moment a live wire reaches them, and don't need a wire placed on their own cell
- Connect every building before your wire budget runs out to clear the stage
About This Game
Power Grid is a resource-constrained pathfinding puzzle: unlike a maze where you're looking for any valid route, here every wire you place is a cost you can't get back for free, and connecting three separate buildings independently is almost always more expensive than finding the one shared route that serves all of them. The game never tells you the "optimal" answer — it just gives you a budget tight enough that careless placement won't clear the stage, and generous enough that a genuinely efficient route always will.
Because buildings themselves are always conductive — you never spend a wire on the destination tile, only on the empty cells leading up to it — the last stretch of any branch is effectively free, which subtly rewards planning long trunks that end as close as possible to multiple buildings at once.
Why We Built It
Real electrical and network infrastructure design is fundamentally a Steiner tree problem — connect a set of required points using the least total wire — and it's a genuinely interesting optimization challenge even in miniature. We wanted a puzzle that let players feel that "aha, I can share this segment" moment without needing any background in graph theory to get there. The visual feedback of watching the network glow green as soon as a path completes does most of the teaching for free.
We kept the connection rule as simple as possible on purpose — any two adjacent non-empty cells conduct, no orientation or tile type to think about — because Circuit Repair, elsewhere on this site, already covers the rotation-puzzle version of "connect the power." Power Grid is the placement-and-budget version of the same underlying idea.
How It Works
Every stage defines a plant position, a set of building positions, and a wire budget computed from a reasonably efficient hand-planned route with a small safety margin built in. Connectivity is recalculated after every tap using a flood fill from the plant through any chain of adjacent non-empty cells — wires, the plant, and buildings all conduct equally, so a partially built network lights up incrementally as it grows rather than only at the moment of completion.
Placing a wire only costs budget when it turns an empty cell into a wire cell; removing a wire immediately refunds that budget, so there's no penalty for backtracking out of a route that turned out to be inefficient. The stage is marked complete the instant every building is present in the flood-fill's reachable set, regardless of how much budget remains unused.
Tips & Strategy
- Find the building closest to a straight line from the plant first, and build toward it — that becomes your trunk, and every other building's branch gets shorter if it can tap into that trunk instead of starting fresh from the plant.
- Count cells before you commit. It's cheap to trace a route with your eyes and count required wires before tapping anything, and much cheaper than placing and un-placing.
- Diagonal-looking connections don't exist — only up, down, left, and right count as adjacent, so a route that looks like a shortcut on the diagonal is actually two wires, not one.
- If you're running low on budget with buildings still dark, check whether an already-built branch passes near the remaining building — a two-wire spur off an existing line is almost always cheaper than a new route from the plant.
Ideas for Improvement
- Terrain costs — certain cells (rivers, hills) that cost two wires instead of one, adding a weighted-pathfinding layer to the budget math.
- Blocked cells — a small number of permanently unusable cells per stage that force a specific detour rather than a free choice of route.
- Efficiency star rating — bonus recognition for clearing a stage using the true minimum wire count, encouraging a second, leaner attempt.
- Sandbox mode — an unlimited-wire free-build mode for players who want to explore layouts without the budget constraint.