Are TF2 Achievements servers legal for Steam leaderboard?

[Doopler]

im just playing random community servers and i saw some servers that give you possibly every achievements (not every) and its real. I know there is some achievements thats for limited events that got disscontinued but im kinda nervous i get leaderboard banned

will i dont get banned for this? Im really curious

 

[x3sphere]

Those are not allowed, but the most that would happen is that we invalidate the game and not remove you from the leaderboard.

 

[Aze07]

As a former tf2 player with gazillion hours, I could say we (yes we) all used those idling free achievement servers to get free items ! Most of us were broke and wanted free weapons and the easiest way was to get in those servers. I am a new user and I saw an astronomical bump in one specific day, turns out it was TF2's fault lol