A cool head, and the weight to back up your words.
When you bark an order or warning, roll +CHA.
7+: They must choose 1:
Do what you say.
Dig in, take cover, or flee.
Attack you.
10+: As above, and you sense which one they're about to do and may act first — gain advantage if you do.
This work includes material from Stonetop by Jeremy Strandberg, published by Lampblack & Brimstone, licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.