Bellum atrox

Spring 451. Attila has crossed the Rhine with the peoples of his empire. You are Aetius, the last great general of the Western Empire, and you have almost no army of your own.

Bellum atrox is a documentary solitaire game about the campaign that ended on the Catalaunian fields. Its title is Jordanes' description of the battle: bellum atrox multiplex immane pertinax, "a war savage, manifold, monstrous, stubborn". Your army is a coalition of old enemies: the Visigoths, whom your generals fought twelve years ago; an Alan king suspected of treason; Franks and Burgundians who also march with Attila. You have to feed them, persuade them and keep them, and get them to Orléans before the walls fall.

The sources disagree, and the game lets them.

• Orléans is relieved before the walls are in danger (Jordanes, with the earthworks), as the walls shake (Gregory of Tours), or after the Huns are already inside (the Life of Anianus), depending on how you played.
• The field is where you fight: the Catalaunian fields, Mauriacus near Troyes, or "not far from Metz", and the chronicle names the source that puts it there.
• The wagon fort. Attila is shut in his circle of wagons beside a pyre of saddles. Jordanes says the allies first meant to starve him out. Then the chroniclers give two reasons why Aetius let him go: the balance against the Goths (Jordanes), or a trick to keep the spoils (a continuation of Prosper, and Gregory). You choose among all three, and 452 answers.
• The epilogue: Attila in Italy and Pope Leo on the Mincio, Attila's death in two versions, and the emperor's knife in 454.

Every card links to its source. Each card opens the passage it comes from on the documentary site The Catalaunian Fields, 451 (doi:10.5281/zenodo.23218775): Priscus, Jordanes, the chronicles of Prosper and Hydatius, Gregory of Tours, the saints' lives, Sidonius, in the Latin beside the English. Where the game goes beyond the sources, the chronicle says "in this game".

An accounting, and a benchmark. The end separates what the field decided (Orléans, the battle, Italy) from what the palace decided (your standing at court, the coalition, the Goths, the spoils, your life), and compares your total with 300 bot games. A strategy guide gives the lessons of 400 games for each approach.

• One role: Aetius. Eight fortnights in 451, then the wagon fort and three years of epilogue; 20–30 minutes a game
• Autosave in your browser; nothing is sent anywhere
• Prototype 0: the numbers are provisional