To intimidate a person or group into surrendering needs a number of successful intimidate checks before combat starts.

The DC of the check is 10 + (target's level or HD) + (target's Wis modifier). If there are a variety of enemies, the GM can just use the most difficult DC, or evaluate the effects on each group separately if there's a chance some enemies might fight even if others surrender.

• First round of checks
  • one success: enemy begins combat as they normally would
  • two successes: enemy typically holds off long enough for another round of checks
  • three or more successes: enemy typically surrenders
• Following rounds of checks (DC increases by 5 for each round after the first)
  • no successes: enemy begins combat as they normally would
  • one success: enemy typically holds off long enough for another round of checks
  • two or more successes: enemy typically surrenders

Modifiers

• +4 if larger than target
• -4 if smaller than target
• -2 if more enemies than characters
• -6 if 2x or more enemies than characters
• +2 if 2x more characters than enemies
• +4 if 4x more characters than enemies