许耽 / Xu Dan (late Han)

许耽 / Xu Dan (late Han) enters the wiki through Hanji 999 as the subordinate who opens 下邳 to 吕布. The city is already destabilized after 张飞 kills 曹豹, and Xu Dan’s gate-opening turns internal disorder into territorial loss for 刘备.

The page is source-scoped to this event. Xu Dan’s importance is structural: without an inside opening, 袁术’s promised grain may have drawn Lü Bu eastward, but the city seizure would have been harder. In the episode, a single internal defection links personal conflict, supply incentive, and command collapse.

Connections

• 下邳, 刘备, and 张飞 - city and command setting.
• 曹豹 - killing that precedes the disorder.
• 吕布 and 袁术 - outside actors who benefit from the opening.
• 粮食诱导式同盟背叛 - concept connecting the gate-opening to the wider alliance reversal.