Between 235 and 284 roughly twenty-five men were proclaimed emperor and almost none died in bed — because Rome had never written down a rule for succession. You now hold the only levers a Roman ruler actually had. Move them and watch the same trade-off appear every time: every fix for usurpation costs money, and every fix for money costs consent. Then load Diocletian’s settlement and see why it looks the way it does.
The leversyour reign
Start from a real year, then drag anything you like.
The antoninianus was notionally two denarii. Caracalla issued it at roughly 50% silver in 215; by the 260s it was under 5%.
Smaller provinces mean no single governor commands enough men or money to make a bid for the purple — and mean many more governors to pay.
One man cannot stand on the Rhine, the Danube and the Euphrates at once. Every extra ruler covers a frontier — and creates another legitimate claimant.
Something near 350,000 in the second century; estimates for Diocletian’s army run from roughly 400,000 to 600,000. Every man must be fed whether or not the treasury has coin.
Requisition grain, cloth, mules and labour directly and you never have to trust your own currency. You also strangle the monetised market and need an army of assessors.
Rome keeps its Senate and its prestige, and loses its centrality: the courts move to where the armies are.