All modes, but from what I've seen of gameplay on the lower difficulty settings on Youtube the potion only mechanic works pretty well, you only have to fast travel back to camp to heal and restock potions every 20-30 minutes on Normal I think. it just sucks majorly on Nightmare due to how much damage enemies deal. Cassandra is the tankiest caharcter and even she loses full bars of health in seconds, and since you only get 8 health potions and 5 regen potions you're out of potions after just a few battles, forcing you to fast travel back to camp to heal and restock your potions, and then you've got to deal with the loading screens which are fairly long on Xbox One. Bioware really didn't think the no health regen, no mage healing skill tree thing over very well I think, I've heard alot of complaints about it.

It's a good game so far overall, but there are several things they could have done to make it better, and the saddest part is that many of those things they could have done to make it better were in their previous games. Health regen and healing skill tress have been in most Bioware games. Another annoying thing is that you have to walk to each piece of loot and all of the crafting resources and pick them up yourself, which is inferior to another Bioware game, SWTOR, where you can send your companions to loot stuff which speeds up looting considerably. Also the game has these missions that you can only do from the war table at your home base, and since the missions are short you contantly have to fast travel back to to your home base then walk to the war table from the nearest fast travel point which is pretty far away, then fast travel back to your questing zone, it's a very slow process, especially since the loading screens are kind of long on consoles. There's no good reason why those missions shouldn't have been built into the UI so you can do them from anywhere, you could do similar missions from anywhere in Bioware's earlier SWTOR.