So basically I've been playing a very lightly modded game of Oblivion for quite some time. I have recently decided that I would like to try using OOO and MMM, and maybe any other mod normally used in conjunction with those two, but first I would like to know a few things. Would I have to start a new character to begin using them? Also, I am okay with mods, but these ones seem pretty complicated, so maybe some step by step installation instructions would be good too. Any help would be appreciated.

Edit: One thing I forgot. Would they cause a significant hit to game performance? I'm playing on a kind of old computer, so That's something I'll want to take into consideration.

I may not be able to answer all of your questions, but here's what I know:

You do have to start a new character. Even if it's possible to load up a save, you really shouldn't want to. Too much stuff changed and is rebalanced, if you combine it with an old save game it will be very much out of balance in a lot of places, and will probably ruin both your save and your experience with the mods.

The installation of these mods always seemed daunting to me too. But really it isn't so difficult. If you can find an omod version of a mod, you can install it really easily with the Oblivion Mod Manager tool you can download. I have no experience with MMM, but installing OOO was simple enough, I just downloaded it and extracted it to the right directories.

I think you can expect a performance hit, but for OOO you can probably disable a lot of the mods that cause this (the ones that focus on improved graphics and such). I have no detailed information about this as I've never tried it myself.

I hope that helps a bit.

I'm not entirely sure, but I think that it's probably best to use mods like this with a new character. When I play, I don't switch out my overhaul mods after starting a new character. This is probably especially true for OOO as even if installing it in an old save did not cause technical problems, you'd need to start from the beginning with the mod to get the intended experience.

As for installing them, installing OOO and MMM, at least, is not really that different from most other mods, just that there's more files to install, the biggest thing that might complicate things, I would say, is the fact that both of these mods have multiple esp files, especially if you want to use the optional components. I'd recommend reading the readme as it should tell you what each plugin does and which ones you need to activate.

As far as what kind of performance you can expect, it depends a lot upon your hardware, and what other mods you're running. I understand that mods like this can cause a performance hit, but I can't really estimate how strong a hit you can expect. I'd just try it and see, and if you find your performance unacceptable, you can try lowering graphics settings, turning off other mods that might cause a performance hit, or try using mods like Streamline that enhance performance. In the case of OOO, you could also considering the lite version and avoid using some of the more system intensive parts of it. You could also use the reduced spawns esp for MMM as the increased creature spawns the mod adds by default might hurt your framerate.

The OMOD ready versions and the OBMM make installation pretty easy.

And both have detailed instructions.

Technically I don't think you need to start a new character, but in practice is probably best. Lot's is changed and rebalanced, and it's best to experience it from the start. And not starting a new character might be tricky. You'd need to go into an area with minimal stuff and then wait for about 3 days to a week to let everything reset. And then things might be tricky. It's in the instructions but simpler to start a new game.

I don't know the exact answer. But it seems to me that any performance hit might be caused by more creatures and NPC appearing than the normal game. I remember when I first installed MMM long ago, I was shocked by how many Goblins where now in some of the dungeons. Still it's probably not as much of a performance hit as some of the retexturing mods.

http://tesivpositive.animolious.com/ (Tomlong's site) is what you might want to start out by going through. Not all of it will be relevant to you, but a lot of it will be.

I recommend trying BAIN for installation/configuration/uninstallation of mods. It's better, in the long run, and will most likely save you heaps of stress/time/other. Plus, it's the way more and more mod users, and mods, are going. Still, you do have a choice: OBMM or BAIN. Mind you, both is another way to go...

Check http://tesnexus.com/downloads/file.php?id=35230 out too, for getting used to Wrye Bash's ins and outs, including BAIN, to some extent.

You can either go for OOO (a good option, and not too taxing for older PCs), OOO+MMM, or FCOM. Well, there are other options too, but going by what you've posted - they're the best ones.

I would probably try a pure OOO install, first. And yes, with a new character. Definitely.

If you get used to that - including the install/config - then maybe "upgrade" to either OOO+MMM (a bit easier) or FCOM (the "deluxe" version, so to speak).

If you read the readme files with any given mods, read the OP of the relevant release thread for each in the mods forum nearby, and follow those instructinos to the letter, you can't go too far wrong. Also, people will be more willing to help, happily, if you still need to post, asking questions in the correct mod thread(s). Nothing wrong with doing that - but it's certainly better to do everything you can, and at least try to go about it the right way, *before* asking.

But generally, you'll find - especially if you do that - people in the mods forum are very helpful.

Speaking of which, hope that helps!

The performance hit I got with FCOM(Fran's, Warcry, OOO, MMM) was not too significant, but it is definitely noticeable.

I did exactly like you are doing about two months ago. Had a lot of fun with lightly moded; eventually installed OOO + MMM.

Would definitely recommend a new character for the reasons described. Keep in mind: OOO + MMM is QUITE A BIT MORE LETHAL! I like to play Dead is Dead, so I restarted probably 8 or 10 new characters to (a) learn about the new dynamics and (B) die many, many brutal deaths.

Performance: maybe a bit. My rig is about 3 years old, and even lightly modded there were times I had some performance issues with Oblvion. Following the steps on Tomlong's site for optimizing, defragging, etc., and turning down graphic settings a bit always has seemed to work, even since installing OOO + MMM.

Installation: I too was daunted by these. However, I think it is not nearly as complex as installing either Wrye Bash or FCOM or some of the other more complex suites. I would say, if you use OBMM or BAIN and have a number of other small mods installed already, you won't struggle with OOO + MMM much at all.

The only thing is: try to make sure and find THE LATEST version of both. Skimming through the last few pages of teh RELZ threads for both those mods should reveal what the latest versions are.

I did have some troubles with missing textures because I had installed pieces from newer and older versions, and also because I had some components of MMM turned on that should not have been turned on with OOO. The experts in the mod specific threads are incredibly helpful at sorting out that stuff though.