Maintenance for the week of November 18:
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addons are different they arent changing(modifying) the games code they are adding to it, resulting in some handy features that should be there anyway. get awesome filters for starters, even ui purists need that one.
Edited by dylanjaygrobbelaarb16_ESO on March 2, 2015 3:07AM
If by 'mods' you're referring to the type of game-changing 'patches' you get for off-line games which alter the game code itself then the answer is a big NO!
In MMOs you're not allowed to alter the game client at all.
At best (as in ESO) you can run 'add-ons' which are usually scripted user-created modifications to the UI and other aspects of game-play but only using whatever API the developers make available: if you do anything that physcally alters the game code then you're banned if ZOS detect it.