Housing - Obviously. WS had the best housing but I don’t want to get into that much here. I want to focus on other things WS got right that I’d like to see in WoW. And housing isn’t a “small thing” anyway.
Quest item use button - Press this one button and you use whatever quest item is relevant for the situation. For example, in Zereth Mortis there’s a quest to scan balls with a ball scanner and there’s one to reveal dreadlords with a dreadlord revealer. Even if you had both in your quest log you’d just hit G and the game would use the right item for your location or target. (I think it was G but obviously players could change it).
Costumes - You’d get several costume slots and you could freely change between them anywhere at any time. WoW could do something similar by giving us costume slots to mog. It would still cost gold to mog these other costume slots but then we could switch between them anywhere at any time.
Vacuum loot button - This one is a little tricky since it does something that’s a big perk of Engineering, and adding it for everyone standard would take that away. But it might be worth it. I dunno. Anyway, press a button and loot everything in range.
Dyes - I know this isn’t an easy add, but I think players would understand if armor dyes only worked on gear added after adding dyes. So, the sooner adding dyes is added the more gear could be dyed in the long run. Basically, this is a the sooner the better feature
Mount modification - In WildStar all mounts had a front, back, right, and left attachment point for mount modifying addons. They ranged from normal stuff like what looked like storage containers or saddlebags to stuff that could turn your mount into a noodle delivery vehicle.
(Here’s a mount with various things attached:)
Of course, like dyes, it would make sense that older mounts wouldn’t work this way since it would require going back and reworking all of them, and that’s just nuts. However, the sooner they make something like this for new mounts the more fun we can have in the long run.
Also, in WoW I could see the attachment point number and location varying from mount to mount. I don’t know that horses really need an attachment point on their heads, for example. Maybe WoW mounts could just have left, right, and maybe back points.
OmniBits - A rare-ish currency that could drop from just about any game activity and could be used to buy items off the game shop. I realize we can already use gold to buy items off the shop in a roundabout way. This could be a second little bonus.
This is more of a runner up thing to add. It doesn’t add much and it might be too confusing to have this and the ability to buy stuff with gold, and I’d rather keep the gold option. It’s just, OmniBits always felt good to get and it was fun saving them up and turning them in for cosmetic stuff.
