I wish I could have a fifth party member, tho. I really want to be able to carry both Morrigan and Wynne, because Wynne's healing magic is incredibly useful, but with as much as you're outnumbered in this game I hate having half my party not being able to survive melee combat....
You just need tank, DPS, harry potter and healer. The tank can be Alistair, Sten or the dwarf. DPS doesn't leave much choice; either Leliana or the assassin elf, because you want those locks open and traps disabled. Mage is a must have (not much choices in this department). Wynne is a must have.
Tank attracts everyone's attention, handyman gets the locks open and clears the pathway, mage keeps the crowd entertained and healer keeps the party going on.
The mage should have some nice area effect spells that do and do not affect friendlies.
Some nice spells and combos:
Cone of cold & stonefist, which is also handy for Wynne: with this you can freeze multiple enemies and kill a white labeled enemy with stonefist - Wynne can shatter 2nd enemy without stonefist draining too much mana from healing. A negligible loss of mana.
Cone of cold is also effective at keeping enemy/enemies frozen almost constantly by recharging almost as soon as the effect ceases. Very handy against higher level mobs that cannot be shattered, but which you want to keep from pounding your party. Many orange enemies - especially mages - can be kept in near constant frozen state until they die. Also large groups can be held frozen until other members of the party are done dealing with their share of the mobs.
Cheap and effective spell that you'll love to have.
Earthquake & inferno: Both are roughly equally large area spells. Earthquake is very effective at keeping every legged creature to the ground (also yourself and the party members, so beware). Once everyone is stuck to the ground you can call in inferno, that will last for quite a while. This combo can kill alot of enemies in one go. Any stragler that makes through can be easily mutilated by the party. Even better, if you can keep the stragler in the fire while pounding it without catching fire yourself.
Wynne can be nice with glyph of paralysis and glyph of repulsion. Can buy some time at critical moments.
Dispel magic is a must have - crushing prison can be a real pain in the bellybutton without it.
Grease & fire: I haven't tried it, but sounds pretty much the same as earthquake & inferno, except in a smaller radius. I prefer the larger radius - more distance to cross while flipping over; hardly anyone makes through
Sleep is a nice spell to control the crowds. It will last for quite a while - as long as the sleepers aren't hit by anything. This can be coupled with walking nightmare, although it can be often confusing to figure out who's your ally - you don't want to kill them outright while another mob is beating you up. Either let them sleep or give them nightmares. It may be the best to use walking nightmare against mobs in the back, so they will be more likely to fix onto their friends near by instead of your party, which would be a waste of a spell.
