Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - General HARD difficulty, what changes exactly?

I've noticed the 25%(?) HP penalty, is there anything else? Do enemies have more HP as well? Are they smarter? Does anyone know in detail?

Enemies get a +20% chance to hit you, you get a -10% penalty to chance to hit them.

Is it viable to play on hard with 1x lonewolf and one companion?

I plan on exactly doing that.
Hard mode doesn't seem to add too MUCH difficulty, so it's perfectly doable. I did fine in the beta on hard with 1 lone wolf.