The Elder Scrolls IV: Oblivion - Imperial City Arena Strategy

Imperial Arena Fight Strategy - Conjuration

If you're playing Elder Scrolls IV: Oblivion and having difficulty in the Arena fights because you are a spellcaster and weak in combat skills, you may want to try this tactic:

Enemies in the arena differ from enemies elsewhere in that they almost always ignore summoned creatures and go straight for the player. One tactic then is to summon a creature and then go on the defensive. This has several benefits:

When you have your shield up, hand-to-hand combat enemies will typically strike less often while they wait for your shield to drop, or try to move around your shield. This reduces the overall amount of damage they are sending your way.

Enemies ignore the summons, and do not even try to block or dodge attacks. They will steadily be whittled down in health by your summons.
Enemy archers do not move aggressively, and once they draw an arrow and hold, they often move slowly. It is then easy to evade their line of sight by ducking behind a pillar.

Once the enemy is at low health, you can either try a quick spell to finish them, or stay on the defensive and let them drink their health potion (if any).

Bring health potions to restore your own health if necessary, and sorcery potions to re-cast your summons a few times.

I used this tactic to breeze through most of the fights at level 4, using Francesco's Levelled Arena. Because I was using a levelling slow-down mod, I did not gain any levels while advancing in the Arena, and stayed at level 4 all the way through.