Tes4Mod:Mod Installation

Of all the steps in mod installation the most trivial is when you actually use the "activate," "install," or "extract" command that puts the mods' data files and plugins into your data folder. The bulk of the process occurs before that point. You may have already started the first, downloading the mods from the various upload sites. While, doing that, however, you should be considering the next three steps: 1) Does the mod need to be repackaged 2) What is the order in which these mods need to be installed? 3) What configuration should I choose? If you have answers for all of these questions, then you are well on your way to preventing your modded Oblivion setup from blowing up in your face.

Does the mod need to be repackaged?
The ease with which this question can be answered depends on whether or not you are familiar with the download and the method by which you install your mods. If the download is labeled "OMOD," an OBMM user does not have to do much of anything. Other users would have to first convert the OMOD to an archive before having the capacity to do anything with it. If its label is "OMOD-ready," then OBMM users should still have almost zero work to do, but BAIN and manual install users may luck up as well because the file is an archive; however, there is no way to tell whether or not the mod is packaged "nicely." "BAIN-ready" is the equivalent of "OMOD" for BAIN users; however, it is also organized such that writing an OMOD script to install it or manually installing it while reading the ReadMe should be fairly simple. Mods labeled "Manual" or lacking either of the other labels are simply archives that the user may have to repackage. If the mod is simple (only has a single configuration) and is packaged "nicely" then the work for all users is fairly simple. In all other cases, extra steps should or must be taken, and the rest of this section contains guidelines that will help.

Notes
"Nicely" packaged - The top level only contains a "Data" folder OR the default folders and plugins OR BSAs (default folders) and plugins
:Notes: For OBMM users a single ReadMe (or text file) can be at the top level with the "Data" folder.
Default mod folders: Menus, Meshes, Music, Shaders, Sound, Textures, Video, a folder that contains INIs, etc.
Simple package - It contains only one installation configuration. All data files and plugin(s) have to be installed. (i.e., only has one ESP and some data files to install.)
:Notes: Simple packages are "everybody-friendly."

In the case the mod needs to be repackaged...

Manual installation users must always check the mod's structure before installing the mod. Often, this can be achieved by reading the mod's description or ReadMe on the mod's upload page. Otherwise, extract the mod to a temporary folder and review the ReadMe for instructions on how to install it. If the ReadMe does not include instructions, that is bad on the author's part; however, if you still want to use it, it is not too hard to figure out the archive's structure after having extracted it. Look for the default folders and the plugins because those are what need to be installed at the Data folder level. Even optional or "extras" folders should contain the default folders.
'''Modder's Resources''' are often not packed in a standard format, whether they are separate downloads or contained in a mod's "extras" folder. You should know where the contents go if you downloaded this. If you are not using these files, delete them or ignore them. OBMM users can add a script to stop the folder or file(s) from being installed. BAIN users can, likewise, add "--" to the beginning of the package or subpackage to have BAIN ignore them.
OMOD files should be downloaded to your OMODs folder. (The default OMODs folder is Oblivion\OBMM\mods.) If you are not an OBMM user, and had the misfortune of having to download one, you need to convert the OMOD to an archive. To do this: 1) Right-click on the target OMOD. 2) Choose "convert to archive." 3) Select the folder in which to place the archive. (BAIN users should choose the Bash Installers folder of course.) 4) Do not bother converting OMOD conversion data when it prompts you.
OMOD-Ready files are basically normal archives, the only difference being that they include an "omod_conversion_data" folder that contains the information necessary to make OMOD creation and installation easer. (Manual installation users should still follow the "Manual Installation" guidelines.)
Executables have to be installed before you can do anything with them.
OBMM and BAIN users should package the mod into an OBMM or BAIN-friendly package, respectively.
All other archives need to be checked for "nicely" packaged structure.
BAIN users can do much of this from the Installers tab; however, if the package's check box is dark gray (invalid) then the mod needs to be repackaged. If the package is highlighted in gray and the "skipped" section shows important files being skipped, the file needs to be repackaged. Simple packages will have white check boxes when uninstalled; BAIN-Ready packages will have light grey check boxes. Neither of those needs repackaging. See the BAIN page and the BAIN conversion examples pages to learn how to make packages BAIN-Ready or to convert them to simple packages.
OBMM users need to review the package's contents before creating the OMOD. You can do that entirely in the mod creation window; however, the space for viewing files is limited, which is especially troublesome if the mod contains many files. If it is a "nicely" packaged mod, and a simple mod, go ahead an pack it in an OMOD. If it is not "nicely" packaged, has multiple configuration options or contains items you do not want installed, you need to repackage or write a script to have the mod installed correctly. (Examples coming soon.)


BSA Loading

Big mods that have many data files sometimes pack them into BSAs. This is common practice for big quest mods, for example. There are two ways to get Oblivion to load BSAs content. The first method is to add BSAs to the sArchiveList in the Oblivion.ini file. Ensuring that the INI-loading method works is tedious due to a character limit for that list, but there are ways around that. Most mods use the second method, plugin name correspondence. Their BSAs are named "  -  .bsa" or " .bsa". (See BSAs and Archive Invalidation for more information.) The common BSA naming scheme when you have to do it yourself is to 1) if you have SI, rename BSAs "DLCShiveringIsles -  .bsa" 2) if you only need a plugin to load one BSA " .bsa" 3) create a plugin "Oblivon.esp" and rename BSAs "Oblivion -  .bsa."

Examples

FCOM recommended renaming options
MMM BSA: "FCOM_Convergence_Mart'sMonsterMod.bsa"
Fran BSA: "FCOM_Convergence_FraNewItems.bsa"
:Notes: The FCOM team recommends renaming this BSA "Oblivion - FraNewItems.bsa" with a dummy plugin. It takes up an extra plugin slot and requires that you create a dummy plugin, but both naming conventions work. The choice is yours.
MMM recommended renaming options (use name of main MMM plugin) Rename "MMM.bsa" to...
MMM: "Mart's Monster Mod.bsa"
MMM+OOO: "Mart's Monster Mod for OOO.bsa"
FCOM: "FCOM_Convergence_Mart'sMonsterMod.bsa"
Renaming multiple BSAs for forced loading (non-SI)
# Copy the blank esp Oblivion\Mopy\Extras\blank.esp
# Put the plugin in your Data folder
# Rename the plugin "Oblivion.esp"
# Rename each BSA to force load "Oblivion -  .bsa"
Renaming multiple BSAs for forced loading (SI)
Rename each BSA to force load "DLCShiveringIsles -  .bsa"
:Notes: SI users can always use the the naming convention above to load BSAs in place of any other naming scheme.


What is the order in which these mods need to be installed?
The importance of load order increases as you add more mods, especially when those mods start overlapping. If you check out the My BAIN Package List page, amongst those packages there may be more than five versions of the same file. However, because BAIN has prioritized installation, you know that the version installed is the one with the higher number in that list. It is a conscious decision on the users part to have that mod "win." It is not as easy to figure out which mod is "winning" with other forms of installation, but the list on that page took days to organize. The following guidelines should help reduce that time for you to part of a one-day modded Oblivion installation, even if you are using the other installation methods. The important thing is to think about, beforehand, which mods should have the last say for different types of files, and which mods contain similar files. The goal of the organization below is to have the fewest logical groupings, while minimizing "exceptions." My BAIN package list is primarily in alphabetical order within subgroups. (Installation order and load order are very different. Plugin interactions are very different. DO NOT base your load order on this ordering.)

General Installation Guidelines
Most mods mentioned in this list are found on Types of Mods . BAIN users, install "later" and "after" means should have higher priority, a bigger number, in the package list. Like wise, mods that should be installed "before" another mod should have lower priority, smaller numbers. The numbers on the following groups match the general priority of installation in the package list.
 

What Configuration Should I Choose?

Many mods contain multiple configurations.  Instead of containing "my_mod.esp", they may contain "my_mod_full.esp" and "my_mod_lite.esp", and you have to choose one or the other. Sometimes the distinction is not quite as clear: there could be multiple folders containing "my_mod.esp" where the folder name mean nothing to a new user of the mod or maybe the mod contains "some_other_mod.esp" and no data files because the mod depend's on a different mod which should already have been installed. Often, after the user ignorantly installs the mod, not realizing a choice should have been made, glitches appear the game, and he or she is then wondering if the mod is broken.  Reading the mod's ReadMe before installation could have easily prevented such mistakes.

Popular Mods with frequently overlooked multiple configurations
Vanilla OR SI and FULL OR Part (Choose one or the other!) Ren's Beauty Pack || Ren's Beauty Pack Hair's Only mz_Shields || mz_shields-SI Dark Dungeons || Dark Dungeons - SI
Vanilla + SI (Install BOTH if you want the SI component) Harvest Flora + Harvest Flora SI
SI - Vanilla (Install the non-SI option if you do NOT HAVE SI) RBP: add RBPNoSI
SI ONLY (Do not install if you do NOT HAVE SI) Enhanced Water HDMI: use Enhanced Water HD instead
Replacers with different names (Uninstall the original plugins, not the entire mod! they do not overwrite the original plugins!) BC: Clocks of Cyrodiiil BC patch, Vaults of Cyrodiil BC patch

Choosing the Right Plugins
...guidelines for what you should do...
Read ReadMes (may want to check the Online ReadMes page)
Make sure you install all dependencies. If you do not, the plugin will have red check box next to plugins in Wrye Bash, indicating a missing master (The only exceptions are plugins with the "Filter" Bash tag, as you are not expected to have all of the dependencies.) The game will crash on load if a plugin missing a master is active.
:Notes: many UL patches can be found here: Unique Landscapes Patches@TESNexus
DO NOT leave unused plugins in your data folder, unless you turn on Wrye Bash's auto-ghosting, which "hides" plugins from the game engine for you.
Do not install a bunch of custom race mods that your PC or companions are not using. Installing many custom race mods often leads to conflicts among them and various quest mods, not to mention they are wasting plugin slots at that point.
OBMM users should add scripts to any mod that has multiple configurations (multiple main plugins or options) that does not already have an OMOD script. It should help prevent common installation errors, if the scripts do not allow you to make certain mistakes. See OMOD Scripts & Script Templates for templates as well as links to other OMOD scripts, a number of which can be found on TESNexus.
Do not install multiple version of the same plugin. If two plugin's names only differ by a modifier, there is a good chance that both should not be installed at the same time. If you are unsure, check the mod's ReadMe.

See Common Mod Installation Errors for more examples.

See Also
BAIN Installation
Manual Mod Installation
OMOD Installation

External Links
BAIN vs. OBMM - UESPWiki
How To Create an OMOD - TESCSWiki <-- more in-depth description of the OMOD creation process targeted at mod makers