Power Grid Route Math: How to Price Every Build

Building is where most Power Grid money goes, and where most counting mistakes happen. The rules are short. The habits that keep the arithmetic honest take a little practice. This lesson covers the rules, a method for pricing a turn, and the small tricks that save Elektro every round.

The cost of one city

A new city costs two things added together:

• The city space. 10 for the first house in a city, 15 for the second, 20 for the third. You always take the cheapest open space, whatever the step. An empty city in Step 3 still costs 10.
• The connections. The numbers printed on the lines between cities. You pay the cheapest chain of lines from any city already in your network to the new one.

Your very first city has no connections to pay. It costs 10 and can go anywhere in the play area that has room.

The rules that trip people up

Connections are not owned. Paying for a line does not make it yours. Next time you build out along that line, you pay it again. Rivals can use the same lines too.

You can pass through any city. Your route can run through cities that are full, or that you skip on purpose. Only cities outside the play area are off limits, along with every line that leaves the play area.

Some lines cost 0. A few neighboring cities are joined by a free connection. You still own at most one house in each city.

Several cities in one turn. You may build as many cities as you can pay for. Each new city can route from a city you built a moment ago, in the same turn. Each one is priced on its own.

One house per company per city. You can never build a second house in a city you already have.

Pricing a turn

The rulebook suggests a trick: stand each new house on its end until you have paid. Here is a method that goes with it.

1. List the targets. Name the cities you want this round.
2. Order them by distance. Build the closest first, so later cities can route from it.
3. Price each one. For each city: its space cost, plus the cheapest line chain from any of your cities, including ones you just placed.
4. Add it up and compare to your cash. If you are short, drop the most expensive city, not the last one you named.
5. Lay the houses flat and pay.

A worked example

Picture a small part of the map. You own city A. Nearby:

• A to B costs 6.
• A to C costs 14.
• B to C costs 5.
• C to D costs 0.

It is Step 1, so each empty city costs 10. You want B, C, and D.

• B: 10 plus 6 from A. Total 16.
• C: from A directly is 14, from B (now yours) is 5. Take 5. Total 15.
• D: from C at 0. Total 10.

The turn costs 41. Now try it in a careless order. Build C first, from A. The cheapest chain runs through B, 6 plus 5, so C costs 10 plus 11, which is 21. Then B from C: 10 plus 5, which is 15. Then D: 10. That is 46 for the same three cities. Same houses, 5 Elektro lost to ordering, because the line to B got paid twice. In a game where players often end “one dollar short,” that is a lot.

Reading the map for cheap growth

When you look for your next cities, look for:

• Clusters of short lines. A group of cities joined by small numbers lets you add each one for little more than its space.
• Free links. A 0 connection is a city for the price of its space.
• Hubs. A city with many cheap lines out of it is worth owning even if its own neighbors look average, because every later build can start there.

And watch out for:

• Long single lines. A 15 or 20 line costs more than a whole city space in Step 1.
• Corners and coasts. A city with one way out means every expansion pays that line.

Step 2 and Step 3 change the math

Once cities open a second and third space, two more things to price:

• Space cost rises. A city you share costs 15 or 20, not 10. An empty city further away can be cheaper than a shared one next door. Do the sum both ways.
• Rivals open new routes for you. Nothing changes about lines, but cities you could not enter in Step 1 now have space. Old shortcuts through a rival’s area become builds.

Showing your route

At tournament tables, and at good home tables, the builder shows the route and the cost before paying, and others check it. The competitive play lesson describes how the World Boardgaming Championships handles it. Try it at home: it catches mistakes and it teaches everyone to see the map.

For a broader look at why every Elektro matters in Power Grid’s economy, our piece on board game balance math is a good companion.