I've always used illusion, it's got a wide range of awesome spells. But then I wonder how different would the gameplay be if I didn't. Invisibility trivializes thieves guild/DB and escaping from difficult encounters. I can just run to the sigil stone/quest treasure and avoid the mobs. Charm spells mean that speechcraft is worthless. Lots of tough npcs? Frenzy them and go invisible. One guy left? Invisible sneak attack...command him and do it again. Fighting with torch? Just throw up a light spell/night eye. Paralyze is a really stong effect, but the high cost of casting it makes it not so overpowered. Silence is also situationly useful.

I'm thinking without illusion, I'd have to be a lot more careful with sneaking. Bribing might still be preferable to speechcraft though. I'd have to think of an alternative for crowd control. It could just mean put the extra points into destruction and use mass aoe damage while kiting them. Conjuration could work, but it's not going to be as effective as frenzy/invis.

Illusion is certainly one of the more powerful skills in the game, and I've found that I have to limit my use of it in some way, to keep the game challenging. So, yes, it is a bit overpowered.

Having said that, I don't think it's the only skill that is unbalanced (or unbalancing...) at high level. Alchemy is even worse; it has Illusion effects and more.

The biggest problem with Illusion is that it is unaffected by the difficulty slider. This, in my view, is a game defect. Conjuration shares this defect; your player character is weakened by turning up the slider, but his/her summon is not.

I was looking at this page: http://www.uesp.net/wiki/Oblivion:The_Hardest_Difficulty_Strategy_Guide#The_Main_Skills

It's an interesting playstyle presented, never engage in direct combat, just influence it with summons and illusion spells, that might be fun to play if you're patient. I actually rarely use alchemy, I just can't be bothered to collect ingredients and make poitions, I seem to do alright without it.

well limit your magicka pool and how quickly you regenerate magicka, that way you'll have to think about what illusion spells to use and what not.

I sort of deal with Illusion by limiting it. Such as Charm. I find it odd that you can cast a spell on someone and they not get really peeved about it. So I don't use it much. Chameleon, I've never used. I sell the chameleon equipment I find. I rely on my characters sneak level and if it isn't good enough, I have to work around it some other way. Invisibility for my mages is used very sparingly. The duration I make quite short and remove the original spell I bought from my spellbook.

Stuff like that helps tone down it's power for me in my games.

Hope this helps

I don't even like the way chameleon looks, and don't use it. (I liked the Morrowind version of Chameleon, where there was a visible difference as the percentage of the effect increased.) Some of my characters use Invisibility; the limitation that it dissolves when you interact with anything helps to keep it from being too game-killing. I don't like the visual effect, though; invisible is "visible" in Oblivion. :rolleyes:

Illusion, like alchemy or destruction, can dominate the game - especially if combined by a powerful character with other skills. I like to think that Oblivion has almost unlimited character development possibilites; one unavoidable side effect is that it can indeed allow for overpowered characters. As said above, the key is to limit things. I like to roleplay my own limitations rather than have them handed to me by the developer. I am so happy to be free of D&D type class and race limits that 'balance' most other games so that I can go any direction I want and provide my own rules to balance things as I see fit.

I roleplay that my character only has so much ability to learn and master differing things. The beauty with Oblivion is that I am the one deciding what those things are. I like to even have differing abilities within the same skill. For example, my character will only summon a couple of different types of helpers. She is really good with drain speed and weakness to poison (destruction), but terrible with fire, frost and shock (also destruction). She is a great healer, but can only cast healing spells on touch due to the intimate bond required to heal. She makes incredible poisons, but her potions svck.

I tend to do something similar with attributes: max some of them and totally ignore others to more sharply define my character.

Don't be afraid to roleplay in your own limitations to adust your level of challenge.

I've found many of the illusion spells to be really too powerful. I personally don't use many of them like chameleon or invisibility. I've used command creature and humanoid quite a bit, but I've started limiting them as well. Command humanoid just might be on its way out to keep the game challenging. Alternatively my character could wear armor in combat all the time to keep it from being effective on any high level enemies. I'm still undecided on the issue.

Charm, there is an effect that my character abuses regularly but I have no plans of getting rid of it or limiting it. Though OuijaU's point has occurred to me several times.

I for one like Chameleon. After fighting everything in dungeons all across Cyrodiil for some time, it′s nice to know my character doesn′t have to do that anymore. He is Warlock in the Mages Guild and not being able to choose his fights feels wrong. All he wants is to explore the ruins, finding old interesting stuff.

He also likes Demoralize and Paralyze, as well as Silence

I only use invisibility regularly with Paxelle, my pacifist mage. She would otherwise have no way to accomplish tasks like closing Oblivion gates, since she can't fight at all, or command another to fight for her. She wouldn't survive, or be able to finish quests, without Paralyze, Invisibility, Calm, etc.