Excellent question, especially from a 'Plank Driver'..( you have the potential of increasing your worth by becoming a real Heli Pilot)!
Slope limits are ignored all to often, and many pilots have been caught out by their lack of knowledge, with some deadly results!
To give you an idea, the UH-60 has a slope limitation of 15 degrees left or right slope with decreasing levels for nose up or tail up conditions!
The Bell 206 doesn't have any slope limitations posted and leaves it to the skill of the operator/pilot to determine!
Many a UH-1, especially after a mod was fitted on to the mast, had a very limited side slope condition, which brought the dynamic rollover condition closer to effect than previously designed!
