"HW rulez" mod (add-on) for HoMM3.

+ Anti-hin-n-ran. When attacking a living player's hero, if the attacker casts a spell in the first round of the battle, the "flee" and "bribe" buttons are disabled for them. This restriction does not apply when attacking AI heroes or neutral creatures. It also does not apply to AI.

Couldn't this option be implemented as a checkbox? Sometimes, I'd like to quickly calculate the cost of a bribe and whether it's worth sacrificing more troops, but this possibility is lost after the first cast... Or, the "yes" button could be blocked after the "bribe" button is pressed.