As a sober injured party facing an intoxicated wrongdoer, your starting position is strong.
Where your opponent was intoxicated and thereby violated FIS Rule 2, their liability share increases. Alcohol is an aggravating factor in the fault assessment. Your damages claim under Sections 1325 ff. ABGB is established in principle, provided there is a causal link between the intoxication and the accident.
Key steps: secure evidence immediately (photos, witnesses, slope-rescue report). Have any blood-alcohol test of the opponent documented. Obtain legal representation before any interview. The better the documentation of the opponent's intoxication, the stronger the position on apportionment.