The goal

Build Sofia's metro from the first 1998 tunnel to the whole network. Each era is one real line's story: the red line west and then east, the second diameter in 2012, the branches of 2015, the third diameter in 2020, and then the city is yours to build freely. The game is finite and has an ending, and your trains keep running after it.

Money

Fares are in leva (lv), the Bulgarian currency. Passengers pay per kilometre they ride, the moment they board. Every train and every station costs upkeep each second, so a network you cannot fill is a network that drains you. Nothing is billed until your first departure: the line is not open yet. The game keeps its books in leva throughout, as it did when the metro opened.

Trust

The city's patience with you, earned slowly by covering more of the region with useful service. Coverage, the percentage beside the clock, is the share of the city within reach of a station; crowded platforms count for less. Trust cannot be bought. Trust pays for the things money alone cannot: chartering a new line, upgrading a station into a Hub, and advancing to the next era.

It has a ceiling: exactly what the next era asks of you, shown beside the number. Once you are full you earn none until you spend some or move on, so trust is something to use rather than hoard. The last era lifts the ceiling for good.

Beat the first era and the council sits. Its corner button opens a tree of decisions that trust buys outright. A decision is permanent and keeps paying its effect, and some decisions unlock others, so what you take shapes what you are offered next.

Riders carried

Every passenger you have ever delivered to their destination. This is the number the eras ask for: reach the target, spend the trust, and the city moves into its next era.

Building

Drag either end of a line anywhere on the map. The pulsing dashed ring is the next real station, staked out by the city with its real name and the full demand of its neighbourhood: Vardar after Konstantin Velichkov, then Zapaden park, then Lyulin. Only the next station along a line's plan is ever staked, so you find the line as you build it. Right-click a line end to demolish it.

The city builds to a plan. Until the 1998 line to Slivnitsa is finished, only staked stations may be built; finish it and you may place your own stations anywhere, for whatever the label says they are worth. Each era also expects its line complete before the next can begin, and a demolished stop on a historic line counts against you until it is rebuilt.

Once you may build anywhere, hovering the middle of a line segment offers a ghost stop with a plus. Click it to splice a new station into the tunnel you already dug, for the price of the station works alone.

Cost grows along the line you are extending, so a long line gets expensive; a new line starts cheap again.

Chartering a line creates that service and gives it its first train. It does not unlock general building: follow that new line's coloured end to its own staked continuation. When two ends can reach the same stake, choose the line from the small colour-labelled choice beside it.

On the map: every station you have built is a hollow circle, drawn larger at the two ends of a line. The tinted disc around it, in that line's colour, is the area it serves; it widens with the station's tier and its entrances. A thin outer ring with a solid centre marks a Hub or a place where two lines meet, as Serdika is. A greyed circle is a stop you placed off-anchor, between the real ones. A dashed ring with a name is a real station waiting for you.

Running trains

Ring DEPART (or press space) to send a train out. Hiring drivers automates it. Each line shows how often it sends a train: more trains, faster stock and a tighter timetable all shorten that number, and a timetable also stops trains bunching into convoys. In the Network panel, 15 s is the service interval and 14 🚆 means fourteen active trains. The number between − and + is the train target for that line.

Time, rush and trouble

The clock by the coverage number runs the city's day. Each rush hour is graded on how many of its would-be riders you actually carried, and a clean rush earns a little trust. From 2012 the signals sometimes fail: the struck station stops boarding until it passes, or you send the repair crew for a fee. None of it is fatal; all of it is information.

The offices

Later purchases open new pages and powers: the statistics office keeps graphs, records and a ledger per line; the works department places bulk upgrade orders from the Network panel; service patterns let you mark stops for the express to skip (set it in the station panel, trains then alternate full and express). Beat the first era and the line diagram appears in the map corner, hanging your network on the platform wall as a proper diagram. Watch the map for quiet purple diamonds, too. The city has odd corners, and noticing them is worth something. And now and then a golden train rides one of your lines. Catch it with a click for a small thank you from the city.

Managing the fleet

A new train goes where it carries the most riders. With Auto on, the fleet also rearranges itself whenever the network changes; press + or − on a line to set its count by hand, which switches Auto off, and Balance hands the fleet back to the automatic plan. Move them yourself in the Network panel: + orders a train in from the line best able to spare one, − sends one to the line that needs it most. A transfer costs a small depot fee, and if every train is out running, the order waits and executes the moment one parks at a terminus; click the pending marker to cancel it and take the fee back. The fleet ceiling rises with every era, and the price of each new train is the real limit.

Mothballing parks an idle train in the depot: it carries no one and costs a fifth of its upkeep until you reactivate it. If money runs out for a while, the city mothballs a train by itself and says so; reactivate it once you can afford it.

Stations

Click any station to see what it is doing: how crowded it is, where its passengers are heading, how many gave up waiting. Upgrade it there. Entrances widen its catchment, gates load trains faster, and a higher tier is what lets lines meet: two lines can share a Station, and a Hub can found an entirely new line.

On the map, the dots beside a station are its waiting riders, one dot each; past 18 they turn into rings of ten, marked ×10. A red −5 floating off a station is five riders who gave up waiting. After each rush its grade, A (best) to E, says how well the network held it.

Away from the game

With drivers hired, the network keeps earning while you are gone, at a fraction of what it makes with you watching. It is safe to close the tab; progress saves itself.

What the icons mean