How does CIS work?

The “Circulated in Skyrim” (or “CIS”) mods replace items in Skyrim with leveled lists (LVLI), which makes it possible for different items (such as modded content) to be spawned in place of vanilla content. Before I can describe how CIS mods work in detail, you’ll need to be well-acquainted with leveled lists (LVLI) and outfit templates (OTFT).

Leveled Lists and Outfits

Leveled lists (LVLI) are lists of one or more items that Skyrim spawns randomly and/or based on the player-character’s level. They are used for anything between filling lootable objects (such as barrels or chests) and equipping NPCs with gear. Outfit Templates (OTFT) determine what weapons and armor an NPC spawns (and is equipped) with. They contain one or more items or leveled lists (LVLI).

Core Files (or CISCore)

All CIS patches rely on a set of core files, CISCore. CISCore replaces items in Skyrim’s leveled lists (LVLI) and outfit templates (OTFT) with new leveled lists containing that item. These leveled lists (LVLI) all referred to as “CIS leveled lists”. Mod-content is inserted into CISCore’s leveled lists via “CIS patches”, separate mods which work with CISCore. After creating a Bashed Patch (using Wyre Bash) or a merged patch (using say, xEdit), Skyrim will randomly spawn mod-content in place of vanilla content. . . thereby circulating it in Skyrim. CIS patches also inject new enchanted variants of mod-content into CIS and Skyrim leveled lists (LVLI).

Some CIS patches may distribute items in your game a little differently, but it’s all based on the same method. CIS mods use no scripts whatsoever.

Why have “core files”?

Technically speaking, there’s no need to have “core files” (or “CISCore”) for this method of loot-distribution to work. However, CISCore provides both you (the user) and me (the modder) distinct advantages. CISCore manages outfits (OTFT) and leveled lists (LVLI) which are used by other CIS mods. It also contains custom object effects (OBJE), which are used for custom enchantments. By having these items managed by a set of core files, it makes it possible to update them (and by extension, the whole CIS series) with a single .esp (rather than updating all CIS .esps). On your end (the user), it makes updates a snap! CISCore also reduces file sizes and makes merging the CIS series easier, by reducing the amount of data needed in each CIS Patch.

How do CIS Patches work?

CIS patches inject CISCore’s leveled lists (LVLI) and vanilla leveled lists (LVLI) with mod-content. CISCore is a framework, and CIS patches use CISCore to distribute new content in-game. Every CIS patch is specifically tailored to one or more mods. They are responsible for enchanting (when applicable) and rebalancing the items they circulate in Skyrim.

It takes a lot of work to distribute and enchant modded content, so it’s understandable why many authors don’t bother. With mods like Lootification, one could technically argue that it’s unnecessary. However, mods like Lootification are what I like to call “blanket fixes”. While they do distribute modded content, they only cover-up the problem. Script-based solutions offer much flexibility, but they can be considered “one-size-fits-all” strategies.

Most loot-distributing mods are designed with weapons and armor in mind. They may or may not pay attention to other types of items, and in many cases, they can’t. While they work great with basic sets of gear (such as cuirass, helmets, greaves etc.) they struggle with non-vanilla-based gear (such as “bikinis”, collars, and other “non-standard” gear). They cannot dynamically enchant or rebalance these “exceptions”, and will require user input to maintain in-game balance.

My CIS patches are created by hand, allowing for a greater degree of balancing and edits no “blanket fix” can do. These patches are carefully designed to be balanced in relation to the vanilla Skyrim experience. They rename, enchant, adjust, and distribute modded content into Skyrim. By avoiding scripts, the CIS series won’t (directly) contribute to script latency or lag. CIS patches come in all shapes and sizes, to best integrate modded content into your game.

Advantages of CIS

When distributing new content to Skyrim, there are many ways to do so. I’m going to try to convince you to use my way.

Console Commands don’t randomly distribute items to characters or lootable objects, and they are impractical to use with regularity. Every console command requires user input, breaking immersion for many players. You could use batch commands, but it doesn’t solve any of the problems listed above.
Add Item Menu (or AIM) is a user-friendly way to add items to player’s inventory, but it suffers the same disadvantages as console commands.
Automatic Spells and Increased Spawns (or ASIS) only distributes spells and perks. It will not rebalance them without user input. As a script-based solution, it has a significantly higher chance of causing undesired effects, such as unbalanced encounters or script-related issues.
Lootification does distribute new content into Skyrim, and with great proficiency. However, it does not rebalance individual items by itself, and has limited renaming capabilities. It will struggle with any “non-vanilla” based loot, and is intended for equipable gear. Like all script-based solutions, Lootification is “one-size-fits-all” and suffers similar disadvantages to ASIS.
Wyre Bash doesn’t distribute new content to Skyrim by itself. It merges pre-existing leveled lists together, which exist in vanilla Skyrim and are created by mod authors. Most mods which add items to Skyrim don’t include leveled lists, and thus cannot be distributed in-game by Wyre Bash alone.

But here’s the beauty of my CIS mods. No matter what method of loot distribution you use, CIS should be compatible with all of the above options (and more!) Because CIS uses no scripts, it is (in theory) compatible with just about anything you install.

Disadvantages of CIS

No mod is perfect, plain and simple. I hate to rag on my blood sweat n’ tears, but something’s got to be said.

CIS may conflict with other loot-distribution mods. I know what I just said, but hear me out. While the effects of such conflicts shouldn’t break your game, you may have NPCs spawning with extra copies of items, or not spawning with the full range of items you have installed. Although, you should be able to solve most of these conflicts with a mod merge or patch.
CIS has no in-game or easy-access settings. To edit any CIS file, you’d need to open them via Creation Kit or xEdit and edit them manually. Unfortunately, CIS patches require an immense amount of labor to edit. CIS patches have taken me anywhere from hours to literal days to create. In one case, I spent over one-hundred hours making a CIS patch.
CIS uses a great deal of leveled lists (LVLI), and every CIS patch you install may increase that number and/or the number of entries in those leveled lists (LVLI). Every leveled-list (LVLI) and leveled-list (LVLI) entry taxes system resources, and they may affect frame-rate if called upon in large numbers (such as spawning many NPCs at once).
CIS uses a new .esp for every patch. This problematic for the avid modder, where .esps are a valued commodity. If you are in need of free space in your load order, I highly recommend merging all CIS patches. Do not merge CISCore with your CIS patches. . . I’m not sure what would happen. It might be okay though.