You're in charge of the reactor in Unit 4 of the Chernobyl Nuclear Power Station. Manage the nuclear fission reactor so that stable radioactivity levels create steam that turns a turbine and makes electricity for the grid. Simple right? Just make sure to avoid a meltdown and a core explosion and handle any unexpected events along the way...
Same flawed reactor in every mode
Like Legasov's cards: red cards push radioactivity up, blue cards push it down. Aim for balance.
More insertion → radioactivity down. Less insertion → radioactivity up.
Inserts every control rod at once, except any that have jammed. Use it to stop a radioactivity spike.
The more pumps powered and running, the cooler the reactor and the less steam. With no pumps running, the reactor boils off the remaining water. Beware.
Converts steam into electricity. The water pumps run on power from the grid. In a power cut, disconnect the turbine from the grid and use the electricity it produces to power the pumps. Running at high steam for too long can trip the turbine.
At low radioactivity the core can't burn off xenon, a byproduct of fission. Xenon builds up and drags radioactivity down further, which lets even more xenon build up. Withdrawing control rods and cooling the fuel can counter this, but be cautious: once radioactivity rises, the xenon (and the brake it was providing) can burn off quickly. It's best to avoid high xenon levels.
We need to complete a safety test, a box-ticking exercise for the executives. It involves lowering power output, disconnecting the turbine from the grid and measuring how much power the coasting turbine can supply to the water pumps. The deputy chief engineer will be on site to instruct you. It would be wise to keep them happy and get the test done.
Avoid all of this and you'll survive your shift when the clock runs out.