I never suceed...
It looks like you're fighting the big boss of act one but it's only a random encounter.... Don't know why they're doing things like that...
It's just a cascade effect from Larian's decision to change DnD action economy, they reach you due to jumping(because jump distance str based and BA, not movement). Wait for Frost Giants with 23str to appear, they will jump by a half location right to you wizard.
