Thanks. I never really used the tactics in DAI. Far too intellectual when I could just charge in, though it's possible that from the lack of specific commands, tactics seemed more effort than they were worth, whereas DAO allowed the player to make valuable decisions regarding party combat.The most essential difference is in the tactis. With 25 sloths of commands, you can customize how each member of the party will act, who they should defende, attack, what type of enemy they will attack, when they should use each single of their abilities, etc. It's a very extensive list of what you can do, and if you do right, you don't have to micro-manage the combat.
The tactics system in DA2 is better than in DAO. It's more polished.
I want very much this system to combe back, but I lost hope already.
Then there's the healing system. In DAO, not only mages have healing abilities, but you can carry an infinity number of healing potions and mana/stamina, your health also is restored automatically after battle. While in DAI, mages use only barriers and you can have only 8~12 healing potions, you won't find them to loot, but you can replenish them in the camp without any costs.
There's also the matter of items like traps, bombs, types of arrows, talents, skills. Much more variety in DAO.
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Although there's certainly a lack in DA2, I prefer the combat there over DAO because of what they did with rogues. I feel like I owned the battlefield.
I suppose there being no cost for restocking healing potions in DAI is balanced by the palaver of having to travel back to camp and then out again and by their limited inventory number, as well as the partial (complete?) removal of healing abilities.