To be honest I cannot believe I haven’t mentioned sooner. It was introduced in City of Heroes and is called Exemplaring or Reverse Sidekicking. Both terms are tied in to CoH’s penchant for naming features with a comic book flair.
Sidekicking in in CoH is when a higher level character teams up with a lower level character and, in the process, boosts the lower level character’s effect level up to near that of the higher of the two. It is so named after some of the famous duos in comicdom such as Batman and Robin with Robin being the sidekick.
This is a good idea but, really, not exceptionally needed since higher level characters could just tag along on the missions the lower level character has. However there is a problem with that. The absolute boredom of fighting in missions which pose no challenge to the higher level character. That is why the reverse, Exemplaring, is the forgotten feature.
Exemplaring is when a high level character has their effective fighting capabilities lower to those of the lower level character. This allows them to complete the missions of the lower-level chracter in a manner that is challenging and thus fun.
In all my years of playing MMOs the most prevailant impediment to effective grouping has been the snooze-fest low level content is to high level characters. I have had lots of people who were willing to help me clear out a few quests if only they weren’t so overpowered it was no fun for them to do it. If the challenge was there, if they could shrug their uber power for the sake of fun, I (and many others) would find group content while levelling up far more accessable and fun.
City of Heroes introduced the concept shortly after its release in 2004. Since then I believe the only other games which have followed suit have been Everquest 2 and the soon-to-be released Star Trek Online. Neither of those are surprising as EQ2 prompted another MFF entry and STO is being developed by the same company that made CoH.