Variables¶

A power cut in the Shades is one thing, whoever describes it. Simnel calls it customers off supply, the water company a grid outage, the clacks men a power cut, and the hospital power cuts, plural, because it has had more than one. The game keeps one name for it, customers off supply, and uses that name wherever a power cut does anything.

Same words, different things¶

Congestion means three things in Ankh-Morpork. At a clacks mast it is messages queuing for a tower that can only send so fast. At a substation it is a grid asked to carry more than its wires can bear. On Misbegot Bridge it is carts nose to tail. Three problems, three cures and one word, and a game that merged them would send the bridge wardens out to mend the wires. So network congestion, grid congestion and road congestion stay apart.

Demand splits the same way between electricity and water, inspections between bridges and buildings, and response time between the ambulance and the Watch.

Different words, one thing¶

Masts lit and masts dark are one thing seen from opposite ends, and the game keeps masts dark. The generators in the better districts and Nap Hill’s private supplies are the same diesel engines, seen from the top of the hill, and the game counts them once, as private supplies.

Where a variable lives¶

Political pressure belongs to the whole city. Trust belongs to a district, and trust in the Shades can fall while trust on Nap Hill holds. Whether the Cockbill Street Pump is working belongs to one building. A box never names its district. Every district has private supplies, and Nap Hill has a great many of them.

Each is measured against an ordinary day. Some pile up slowly, like trust, cracks in the walls and the cash in the Royal Bank’s vaults. Some are worked out afresh every hour from the others. A few arrive from outside and cannot be argued with, such as rainfall and the wealth of a district.

Deciders¶

Some variables are decisions. A few are the Patrician’s: official alerts, allowed investment, emergency lending to the bank, the deposit guarantee. The rest belong to other people. Landlords decide whether to repair, banks whether to lend, the hospital whether to open its corridors, the Grand Trunk whether to skimp on maintenance this year, and Vimes whether to take an interest.

The Patrician can press anyone with a door to knock on: the companies, the guilds, the merchants, the landlords, the hospital and the Watch. It costs political capital, and each pushes back as hard as it dares. Vimes dares a good deal. The public has no door. It moves only when something moves it, and the outsiders arrive when the trigger sends them.

Still to decide¶

An upgrade on Nap Hill widens the gap between the districts, and the same upgrade in the Shades narrows it, so one arrow carries a different sign in each.

How hard each arrow pushes, how long each delay lasts, and which variables start away from an ordinary day are still open.