I'm working on repackaging my Realism Tweaks. In my current release, there are 9 independent modules (esps). The problem is that this can make it really difficult to update and to keep things balance when users are using just pieces of my full mod (it also makes it really difficult to track down users' bugs).

So what I plan on doing is making one large core module . . . which would be necessary (it would be the Master), and a few optional add-on modules (esps).

My question is: Should my Core module be an esp or an esm? What would be the advantages and disadvantages of either? I've tried to search for this on my own, but I haven't been able to find anything (part of the problem is that both terms have only 3 letters, so I can't do a forum search) . . . not here, or in the GECK wiki.

I have limited experience in modding compared to most people on here but I would say that one advantage of an esm is when creating NPC's. The body and neckline match is much better with an esm file. Of course esp's have an advantage when it comes to conflicts as the user can simply move the esp to the bottom of the load order to win a conflict, something they can't do with an esm. For me I always make my mods an esm if it is creating NPC's but for others I would tend to leave it as an esp. But that's probably just me, but the improvement in head and body match with an esm is often really striking.

If you went the esm route, the full tweaks could be in the esm. Any esps that used this esm as the master would be used to toggle off, or override items that are in the esm, or add items that are not in the esm. The advantage is that all your esps know about all objects in the master. The disadvantage is that you have to turn off the esm bit in the main module to edit it in the Geck. Then you have to remember to turn it back on before editing one of your esp's or the Geck will remove the master from your esp!

If I were you, I would make the main an esm. This ensures that people have it when they use your mod, and removes the user error of them not, messing everything up. It would also prevent them from changing anything in it (without knowledge of how to make it an esp again) and possibly creating errors on their own, then falsely reporting them to you.

ESM is the way to go, along with 'cleaned' copies as override .esp's. If you make a copy of your ESM, change its file extension to .esp, then manually add your ESM to the esp's masterlist with FO3Edit, you can then reload, filter, and 'clean' it against the full ESM so it will only contain overrides to vanilla records since your new forms will inherently not conflict with anything. Also, since ESM's have ONAM lists and handle NavMeshes better, it's probably best to have all cell and worldspace edits strictly in the ESM, making for a better performing plugin suite as well as reducing the size of your esp(s). That's how we FOOK'ers do it anyway.

Thanks for all the help, but I'm still a bit lost as how to go about packaging my mod. I'm thinking that the best way to go would be to have an Arwen_Realism.esm, with a matching core Arwen_Realism.esp, so that the two would contain (between them) the bulk of my Realism Tweaks (probably all that is currently in my Main Tweaks, Survival, Localized Damage, and Smarter AI modules; plus all the game settings from the other modules).

And then I would have a couple optional esps for the remainder of my mod (my weapons/armor; Skills/Less_Is_More; and my Reduced XPR modules). And all the esps would have the Arwen_Realism.esm as their master. I would also want the Arwen_Realism.esp to be the second master for all the optional esps.


What I'm most confused about is what to put in the Arwen_Realism.esm, and what to put in the Arwen_Realism.esp. At this point, my mod doesn't include any textures, meshes, or sound files.

As I understand things, my Arwen_Realism.esm should have things that are unique (such as my scripts, quests, messages, and anything else that couldn't be overwritten by other mods); which would mean that it would be a pretty small file. And then my Arwen_Realism.esp would contain all my edited game settings and anything else that I would not want to to be overwritten (so that it could be put near the end of the load order, just before my optional esps).

Is there anything that should be put in both the Arwen_Realism.esm and the Arwen_Realism.esp?
Does any of this make sense, or am I way off base?

Yes, it is a good idea if you intend to create a modular mod or share the core with some other mods in the future. But :

There is no need to put it in both files, as it is redundant. If you put it in the .esp it will override the .esm, so it is useless to place it in the .esm first.
But if you plan to make standalones .esp not dependent of the .esm then it makes sense.

Your .esm should contain all the defaults you can alter in your optional or additional .esp. Then if you want one of the options to alter a value, of course it needs to be in both the .esm and .esp, but if it is the same it is pointless. It is good if it is a new setting but not if it is a vanilla game modification.

Keep in mind any .esp will override the .esm values, and you never know what mess the user will do with it's many mods. It is tempting to try to foolproof your mod by confirming the value in the .esp but even another mods loaded in improper order can change the value or cause conflicts, and if your .esp is intended to modify the value you entered in the .esm then it is useless in the first place.

The major problem is you never know what mess the user will make with it's mods. Fo me, I limit the .esm to completely new things added to the game itself (what could be called resources, used in all mods) , and all modifications to the vanilla game or use of the resources to .esp.

You would normally only have the same items in the esp as in the esm if you made changes to these when editing your esp, and these items are originally located in the esm.

You might think about having one esm for your unique items. Then one main esp module. In this esp module, have a config menu where a user can turn on or off the other modules. And instead of all your other modules being esp's, make them scripts within this main esp that turn on or off the appropriate settings for the module. Then maybe you would have a separate esp for the quest xpr mod to allow users to change the load order of that one.

Thanks so much for both explaining this so well Octarina and RickerHK!

I think I have a fairly good idea of how I should package my mod now.