Fallout New Vegas: Mod Usage Guide
So many people have trouble with their mod list and the reasons for it are many, but the amount of bad advice that is being spread around certainly does not help. Since we modders are usually expected to clean up the mess other people cause and are often blamed for it our selves. I felt I would address this issue directly by helping you players see how mods work and how to spot trouble with your mod list. This guide there for covers modding topics but I have attempted to make it easy to follow for you players.
Given the nature of the topic, it is not always possible to simplify things for players but I will give it a go. Remember if you do not understand something, just post a question on our forum and I'll try and answer it best I can.
When you decide to install a mod, the first question is, where does it go. For Fallout New Vegas, Fallout 3 and Oblivion, the answer is in the data folder found in the games own folder. E.g. Fallout New Vegas/Data or Fallout3/Data or Oblivion/Data, you get the idea. Some modders like my self know you do not know about the Data folder when you first start playing these games so we have our mods install directly in to the game folder it self and we pack the mods so they always install correctly. Leaving you without any need to know about the Data Folder.
But should you need to manually install a mod from scratch, just open up the mods archive, open up the the Data folder and drag everything you find in it, it in to the Game Folders own Data folder, saying yes to any overwrite questions (usually). Everything in the data folder will automatically be copied in to the right place.
It is usually wise to read the mods readme first since some mods come with special instructions and spending 5 minutes reading about them beats spending 2 days trying to work out why your game no longer loads up. This happens a lot and users dislike being told they could have solved their problem days ago if they just read the mods docs first.
Common Problems: Game Fails to Load
Sometimes a game will crash before it reaches the first menu. When an esp file needs an ESM that is not installed, that is the result 99% of the time. You will find disabling the mod that needs the missing ESM file will allow your game to load correctly when the issue is related to a missing ESM file. If you have GECK or the CS for older games installed, loading it up and clicking on the mod will list the ESMs it requires on the right of the screen.
How to safely try new mods.
After installing a new mod never save the game or if you do save, save to a test save and leave your actual save games alone until you have tested the new mod and know it works correctly. By not saving over your actual game saves you play with, you avoid corrupting your saves with errors caused by your mod list. You are basically running the new mod in sandbox mod, so it can not do your original saves any harm until you save over them. Should the mod turn out to cause you problems, you simply remove it and load up your original saves, abandoning your test saves at the same time. Overwriting them with new saves later gets rid of them for good. If the mod turns out to be good, then you just save over the original saves and continue playing having successfully finished your tests on that mod. Again you can save over your test saves later.
Typing Save NameOfSave in the console will let you name your test save so its easy to identify in Fallout New Vegas.
Modding 101 Principles: Player Version.
So you have your self a few mods and your starting to have problems. People are telling you its safe to use tools, patches and merge files and whilst things seem to work, other problems have started appearing. Before long your too scared to install a new mod in case it causes you more problems. You decide you simply do not want to risk it, so you miss out on a good mod because your afraid to use it. This happens because your a victim of bad advice and are likely to be using tools, patches and merge files to "cure" your problems when in reality, your creating more problems for your self by doing that.
There is one basic rule of thumb that replaces all that bad advice and that is never to install to mods you know will conflict with other mods you have installed. But you players often lack the experience need to identify conflicting mods without installing them first so that one rule of thumb which works very well for those who know the basics, is not an option for you. You need a crash course in Modding Principles to stand any chance of being able to employ that rule and get your game stabilized and this is it.
Try and remember these are modding topics and there for complicated in nature, I will try and dump then down to player terms but even I can only do so much.
Your very own Mega Mod
When you look at the mods you have installed you see lots of separate mods, but what your actually looking is a giant megamod you created. Each individual mod you install inserts its code in to your very own and totally unique to you megamod. When that code is bad or conflicts, your megamod breaks and you end up with trouble and lots of crashes. You are the modder responsible for making your own mega mod work, when it fails to work, it is you that is responsible for the crashes and nobody else. Blaming others is what many players do best and thats a great way to annoy other people, usually mods. But the truth is, the mega mod you know as your mod list is your creation. You players made it, you players break it, it is your fault and your responsibility and nobody elses.
So you have to make sure the code added does not conflict and is not bad by testing new mods first to make sure they work correctly in order to keep your mega mod fully functional and your game stable. After all you are the creator of your mega mod, not I and not any other modder, but you.
When your megamod is unstable and simply moving mods up or down the list makes you nervious, then that is the time to rebuild your mega mod from scratch, . It should never make you feel that way, when it does, there is something wrong.
Modding Rules 101
Rule 1: Only one thing can edit an item at a time.
Only one mod can edit an something at a time, if that is an NPC then that means only 1 mod can set that NPCs Stats, spells, packages, equipment or what ever. It is all part of the NPC and the mod to edits that NPC last takes control of it all. Other mods can change spells guns etc, but that cannot add or remove them from an NPC another mod controls unless the mod controlling it is an ESM file.
Merging them would not work either because you cannot have an NPC with a Gunskill of 50 and 90 at the same time. And when making NPCs for specific purposes, the stats modders give them are critical for certain things to work such as quests, so changing an NPC so it runs away sooner, might mean an NPC that should fight to death leaves the area and disappears, preventing the quest from ever completing, especially if the game does not track the AI after it leaves the cell due to an box being ticked on the NPC it selve. Also for Oblivion, the NPC cannot be a Mage and Thief at the same time, only 1 will take effect. So all the talk of merging NPCs in Overhauls is actually bullshit and always has been. One must override the other, that is the rule.
This issue can lead to NPCs not turning up at locations when another mods take them over. This issue comes up a lot with quest mods when overhauls edit all the NPCs, including quest NPCs used by the game. In the past I had to make use of quest NPCs in Origin of the mages guild to make them go to the council chamber to give quests to the player. When other mods edited them too, my quests broke. That fancy feature was not worth the trouble it caused and in hind sight, I should have used the Dialog trick to add lines to those NPCS without editing them.
That trick was used on LT Hayes in my NCR Mod to add my dialog to that quest NPC without editing him my self. So this issue will not arise because of him.
Rule 2: Last mod loaded controls the world.
Think of your mega mod and all the lines of code injected in to it. What ever mod edits an item in your mega mod last, controls that item. Any edits of that item before it gets ignored. So if those edits where important, and they get ignored, you could find your game crashes out when the required code is not found in your mega mod by one of the mods you are using. That mod will appear to be bugged in reality, you have not loaded all of the code it needs to function, so it crashes. Which is a side effect of letting 2 conflicting mods override each other usually and is very common.
Rule 3: New Items.
First new items cannot conflict with anything because they are new to a mod and cannot be used by other mods unless they are in an esm. So usually a new item is as conflict free and as safe as you can get unless they are bugged of course. Any vital item in a mod should be a new item made specifically for that mod in order to avoid problems. This can be as simple as selecting something you want, giving it a new FormID name and then saying yes to the question Create new form, or it can be as complicated as creating an entirely new worldspace. Either way, new = best possible solution to the conflict issue.
Rule 4: Usage Conflicts.
You need to be aware before messing with your mod list (Mega Mod) that a mod does not need to edit something to use it.
This is modding 101, mods can use items without editing that item. If they do not edit an item, no edit based conflict check can will reveal they use it either. Scripts and doors and other things can often use items without even being detected in an Editors usage check and thats the best check there is. Those kind of mods that use something but do not edit it, usually become silent victims of the edits other mods make and frequently are blamed for being buggy or causing crashes. The reality is usually another mod broke them when it edited something they use. This is a very common issue most players fail to understand.
Only a usage based scan will reveal which mods need an item and since mods are just 1 giant list of used items in your Megamod. That means there are going to be millions of lines of reported conflicts to search through and check and that leads to humans making mistakes. So Usage Conflict Tests are pointless.
Rule 5: Edit Conflicts
If you consider your Mega Mod as it truly is, just a list of lots of formIDs with the last edit of a FormId overriding the previous edits, then some issues leap out at you right away. For example, if 5 mods edit a door and mod 3 adds a script to that door so when the player uses it, a quest starts. Using what we know about the last edit overriding all others, we know for certain that mod 5 will override mod 3s changes and that quest will never run. You will never be able to start that quest but your game will functional normally except for that quest.
The nature of overriding mods edits means the reason the modder edited them in the first place is being ignored and the player doing it does not care about what has just been broken. Usually because there is no neon sign advertising the broken mod for them to see. Just a feature that never appears in their game.
So overriding edits in other mods can cause serious problems for your mega mod when code that is supposed to exist is simply never loaded because another edit loads later in the mod list. Moving mods around often helps solve this but in doing so, your going to break one of the other mods instead. So all your doing is choosing which mod you wish to break.
And as I said above, merging does not mean all edits get to work, the 1 edit per item rule prevents the over edits from ever getting loaded. So any override of an existing edit is a bad thing and can cause crashing amongst other mods that edit that item and mods that simply use that item too.
That means Edit Conflicts should be avoided and the best way to avoid them is not to use mods that conflict in this way. It also means the merge ideal is not safe to use because of the dangerous described above in rule 4 and rule 5, thats why merge files tend to cause other problems when used.
Rule 6: Patches
Who makes your patches is the single most important thing you need to know because a patch is a kind of merge file of 2 mods and the skill needed to make the patch depends on the mod being patched. If it is quest mod being patched then you really want a person that knows that quest mod well to do it and not some person that has never made a mod in his life. If it is an eye candy mod then almost anybody can make that patch because it is a simple task.
But as I said above, certain things cannot have 2 values at the same time as I said in Rule 1 and that is especially true for patches.
The biggest danger with patches is the person making them lacks the skill to make the mod he is patching and goes a head and makes the patch anyway without knowing what he broke or even how to fix it. So the best patches to use come from the modder who made the mod being patched. I personally recommend ignoring all patches for third parties because my experience is, those people usually do not know what they are doing nor do they test their work, where as mod makers usually do since it is their mod they are patching and that make a big difference to the quality of the patch and support you get for it.
Practical Application of this Advice.
Get in to the habit of using test saves for a while after installing new mods, that way if the mod doesn't work right or other problems come up, you can remove it and revert to your old saves.
Do not be afraid to try out different mods, the advice here should give you the confidence to test any mod you please and not worry because your save is your "Get out of jail free card", your guarantee that all will be well when the mod is removed. if it needs removing. Of course if you find your self having to juggle mods around to make things work then your doing something wrong. Check the mods readmes, try not to use too many mods that have to be loaded in specific places to work with other mods. That way you avoid the situation where 2 conflicting mods have to be loaded first.
The exception is ESMs which always load first.
But there is rule of ESM creation that says one ESM should not use another ESMs content. But there are also tricks that allow you to do that safely anyway. But ESMS can be a major source of problems if not made correctly. So be aware of it.
When 2 mods do conflict, choose 1 and use that, do not try and use them both at the same time. Remember using the test system described here you can try both mods 1 at a time safely and keep the one you prefer. You can save the other for your next new game and swap them over when your current game ends, thus increasing the replay value of your game. That is what I do btw.
Also it should not be necessary to bash your mod list in anyway if you do this right and make wise decisions as to the mods you use, if you find your self using a bash system to get mods to work, consider your self as having failed Modding 101.
Finally if in doubt, ask the modder, most modders will answer your questions or point you at one of their guides. It is usually best to look for their guides first because I can tell you for a fact being asked the same quests over and over when the answers are in the readme or else where soon gets annoying.
I hope this helps enlighten you players as to how mods work in your game and I home the Mega Mod example makes this pill easier to follow because it is a great way of explaining what a mod list is.