Running Away

[tremorlaine]

I am fighting King Tut. I cannot beat him and therefore have to Run Away. I have a Hireling in play. Must I decide to use the Hireling's ability before the die roll or can I attempt the die roll and then use the ability if it fails? Since cards like Invisibility Potion specify that you can use it after the roll I assume the answer is you have to declare before rolling.