I dunno whatz wrongz with u, I'M BETTER THAN YOU HAHA!!!
...
Sorry I couldn't resist.
One general tip.
Use your party. In all other Bioware games, I just let the party go with default actions, here I micromanage everything and I find that the game is quite challenging, but not impossible, on hard. I'm not particularly good at RPGs, but if playing WoW for 3 years has taught me anything, it's how to play in a party. A few friends of mine who have even more experience than me at RPGs found DA:O to be harder for this reason. Party managing is half necessary at normal and a must at higher difficulties.
high_castle and Jovlo pretty much covered it, but here's a few things I'd like to re-iterate (and add):
- Keep your inventory stocked up on health and lyrium potions.
- Have your tank (or if you're the tank) use taunting abilities so he can soak up the damage and avoid having stray enemies attack lightly armoured allies.
- Use tactics for potion consumption: Health for the tank and lyrium for the healer is important.
- ALWAYS have a healer in your party and a designated tank with a shield. I use Alistair and once he gets those sustained shield abilities up (shield wall) he's unkillable (with Wynne healing him constantly of course).
- Concentrate fire. If you're playing tank, have a rule for the two damagers to follow your target. If you're a damage dealer, follow the tank's target and have the other damage dealer follow him too. 2 enemies alive for the entire fight deal more damage than if one of them dies half way through.
- Protect the healer. I always keep a rule on a rogue to stun any enemy that's attacking Wynne, or I do it myself (I play a rogue).
- Beware of enemy mages! Those fireballs are a *****. Mages are more dangerous not only because of the damage they cause, but because, depending on the aggressiveness set for your allies in the tactics screen, an ally may not chase a ranged attacker. I keep Alistair on aggressive for this reason and also to make him jump in the fight without me having to have to tell him to.
There's no weak class. Even if you build a pure healer and have no combat skills, your party is a very powerful tool and being a healer and keeping them alive is just as important as dealing damage (if not more important). Just remember to keep the composition of one tank, one healer, two damage dealers. You can also carry a warrior hybrid with you or a shapeshifter mage instead of a pure damage dealer. That way, if you come across a large group or a couple of coloured name tags, you can use the hybrid warrior as a tank or shapeshift the mage into a bear and split the damage between your two tanks.
Hope this all helps.