331 BC · Gaugamela, Assyria
The decisive battle that ended the Achaemenid Empire: Alexander drew the Persian line apart and charged a gap toward Darius.
After Issus, Darius offered terms twice and was refused twice. By 331 BC Alexander had taken Egypt and turned east, and Darius had spent the interval raising an army from the whole empire and choosing ground that would let him use it.
He picked a wide plain near Gaugamela, levelled it for his scythed chariots, and waited. Nothing about the position was accidental.
Alexander advanced obliquely to his right, which forced the Persian left to keep extending to match him and pulled it away from the centre. He kept his line flexible enough to absorb the chariots, which the infantry let through and dealt with from behind.
When the extension opened a gap, he turned the Companions into it in a wedge and drove straight at the royal position. Darius fled a second time. On the other wing the Macedonian left was in serious trouble and had to be rescued, so the victory was less tidy than it is usually drawn.
Gaugamela ended the Achaemenid Empire as a fighting power. Babylon, Susa and Persepolis followed within months, and Darius was murdered by his own satrap the next year.
The scenario is about creating a gap rather than winning a line: Macedon manoeuvres to open one and commits everything to it, Persia has the mass to punish a commitment that comes too early.
The commanders, the sides and the idea of the decisive gap are historical. The cards, energy and turn order are game design chosen for a short readable match.