Rules governing knock downs
Long story short I'm building an encounter where the heroes face a giant Roc/Griffon (haven't decided on which yet). I'd really like to have the Roc use it's wings to knock the heroes back, forcing them off the elevated platform that holds it's aerie, or knock them down, so they must use half their action to get back up. Originally I was thinking about skull=knock back some amount of squares, WS= knock down in place and BS= knocked down and moved. This doesn't take in to account that a massive heavily armored barbarian is harder to toss around than a frail wizard. Any thoughts on this? Currently we use BP as a measure of strength so maybe roll a number of combat dice equal to BP and a certain number of skulls is required to keep a hero standing?