When an enemy leaves a tile during simultaneous execution, an attacker ordered into that tile takes the empty ground without combat.
If another formation occupies or claims the vacated tile, the attack advance is blocked instead of damaging the departed target.
No unique screenshot: this rule only changes what happens on a vacated tile during resolution, which renders as an ordinary formation quietly occupying an empty tile — visually identical to normal movement already shown in progress/050-shipped-reconstructed-drawn-route.png (Iteration 17). Linked rather than reconstructed separately (2026-09-15).