Since we do have a lot new members in our ArmAverse, i think it isn't wrong to have a guide on how to install usermade mods and addons. For this guide i assume that you know how to use the Windows Explorer. Well, at first you will have to download them, obviously. Mostly they come in compressed format like .zip, 7zip or .rar format. So the very first step is to unpack it. Personally i prefer the software 7zip for this but you might use other software that can handle the corresponding format. Please note that Windows by default can decompress the .zip format. Modfolder structure While technically it is possible to simply put the addons into the already existing addons folder, this should be prevented. If ever a usermade addons screw anything up, you might have a hard time to locate which addon it is. Using Modfolders will put you on the safe side. Basically the structure looks like this: SteamLibrary - SteamApps - common - Arma 3 - @[i]Modname[/i] - addons The folders up to Arma 3 already exists. You will have to locate it in your Windows Explorer, most likely you will find it here: C:\Program Files (x86)\Steam guessing you did a default install of Steam. Installing Mods/Addons Most Mods/Addons already come with the above structure preset. So after decompressing you might find a folder named @ModName with a addons folder in it and in there you will find at least one file named modName.pbo. Most likely there will be other files like modname.bisign2.pbo, they all belong together. Simply copy the @ModName folder into the Arma 3 directory, like in the example above. If the Mod/Addon doesn't come with the required file/folder structure, you'll probably have one or more .pbo files. Simply create a folder inside the Arma 3 folder. Here you're basically free how you name it. Common practice is to start with a @ as the Windows Explorer always orders folders and files alphabetically and therefor modfolders will always be listed on top. For the rest of the name, you're free, just give it something that is meaningful. If it's a A-10 addon, something like @A10 would make sense. You get the idea. Inside this folder now, you create another folder and this one has to be named addons and nothing else. Inside this folder you copy now all those .pbo file you've downloaded and decompressed. Don't move the .zip, 7zip or .rar files in there, this wont work. It has to be decompressed first. Organizing Mods/addons Organizing Mods is mostly not necessary as they already come organized. For single addons you may organize them in a way you feel comfortable. Say a addonmaker released several single addons over time, it is up to you if you prefer to have them all in separated Modfolders or you create a single Modfolder for all addons of this addonmaker. You also might create Modfolders for specific servers if you wish. This is completely up to you. Enabling/Disabling Mods/Addons This is done ingame. Go to Options -> Expansions. There you will find your Expansions. They are disabled by default unless you enable them in here. Enable those you need and disable those you don't need. Keep in mind that some addons do require other addons to work properly. Also loading order does matter (which is from top to bottom). Say you have a units addon from addonmaker A which requires a weapon addon from addonmaker B. So the units rely on the weapons so these should be loaded before the units. Else you will get a error about missing addons. So make sure that such Modfolders are loaded in the correct order top down. Tools There are tools around, created by very talented community members which might help to get addons easier downloaded and installed. Search the Forums for them, most popular being SixUpdater and PlayWithSix by Sickboy. I wrote this guide intentionally without including these tools as not everyone is willing to install additional software. If you don't mind to, definately take a look at these tools. Addition by Mr. Centipede (thank you, mate):