Level Lists and Bashed Patch

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Original Thread

DragoonWraith Oct 14 2008, 04:08 PM

OK, really? I know several of you in here know what the Bashed Patch does and how it does it, why the lack of explanations?

The first step to understanding the Bashed Patch is to understand how load order works. To understand that, you need to understand the basics of how mods work.

OK, so, to begin - Oblivion.esm. This file was created by Bethesda using the Construction Set (allegedly identical to the one we get to download; I have my doubts about that, but whatever, theirs was certainly similar). It contains lots of data. This data can be divided into several different types. The most basic of these is the "Form". Pretty much everything in the game is a Form. Forms have FormIDs, these are the hexadecimal numbers you use with AddItem if you're using the console to cheat. Items have them, weathers have them, characters have them, cells have them, quests have them. Some things do not - magic effects, for example, are hard-coded. Game settings are hard-coded. Skills are hard-coded. But most everything that can be made with the construction set gets a FormID and thus is a form.

Forms can generally be broken down into base objects and references. Not all base objects have references, and not all types of base objects can have references, but all references refer to a base object. References are the 3D representations of base objects. This has lots of importance all over the place, but is a bit tangential to the Bashed Patch.

The way mods work is that .esp files modify (or add) forms. Most are based on Oblivion.esm, which means they are dependent on it, and can change things about its forms. When Oblivion loads, it starts with Oblivion.esm. After that, it loads .esp plug-ins by date order. It reads the .esp, and when it comes across a form that is also found in Oblivion.esm, it first checks to make sure that the Forms have the same type (reference, weather, item, quest, whatever), and as long as that is true (which it should be), it replaces Oblivion's version with the mod's version. If another mod later changes the same Form, Oblivion replaces the first mod's with the second mod's. And therein lies the problem.

Because it's out-right replacement, if two mods change two different things about a Form, only one of those changes actually gets loaded; the other gets overwritten. In the case of Leveled Lists, this is especially bad - simply adding items to a Leveled List changes the Form. So if two different mods try to add things to the same list - only one is going to work.

What the Bashed Patch does is it goes through the forms, and combines changes from different mods into one mod, so that Oblivion can load all of them. Therefore, multiple different mods can add items to the Leveled Lists and it will work.

Does that explain things? I know I haven't gone into how to decide what mods should be merged; that's better answered by others. But I think some people were interested in this information.