Anyone who is familiar with such games as Mordheim, Necromunda, and Bloodbowl is used to a Handicapping system of some sort to reward lower leveled teams who are fighting greater forces. Forstgrave's lack of such a mechanic is one of the only criticisms I have ever heard about the Frostgrave Game.
I have such an underdog system, am playtesting it, and looking for feedback
0-9 levels difference, underdog recieves 10 bonus XP per level diference
10-19 levels difference 1 level 1 wandering monsters controlled by the underdog wizard, 1 extra treasure, underdog recieves 10 bonus XP per level diference
20-29 levels difference 2 level 2 wandering monsters controlled by the underdog wizard, 2 extra treasures, underdog recieves 10 bonus XP per level diference
30-39 levels difference 3 level 3 wandering monsters controlled by the underdog wizard, 3 extra treasures, underdog recieves 10 bonus XP per level diference
Wandering monsters start in the center of a random table edge during the monster phase of turn 1.
(1-5 your side, 6-10 left side, 11-15 right side, 16-20 opponents side)
Extra treasures are placed by underdog, after deployment, but following the standard treasure guidelines for placement.
Underdog must make earnest effort to earn bonus XP. Routing without earning XP will cause underdog to forfeit bonus XP.
If you get use out of this, or want to offer suggestions on how to improve it, I look forward to the feedback.