Short and Sweet Overview: If an Attunement limit in 5th edition seems arbitrary, one solution might be to tie a character’s number of attunements to the already existing mechanic of proficiency. You would then be able to attune to a number of items equal to your proficiency bonus. Both for flavor and to balance against possible abuses, consider making attunement a more interesting process in which characters use specialized rituals or achievements to gain access to an item’s additional abilities.
One of the more laudable achievements of 5th edition is its success in making the game more scalable and playable at higher levels. Finally, we have a version of the game that doesn’t tend to spiral out of control into a power-fueled slogfest of headache-inducing number-crunching, yet still feels like the game we all know and love. In tandem with this shift in design philosophy, the role of magic items in the game has been toned down significantly, as have the prevalence and power of the items in general.
While I think this is a good design decision overall, one part of the whole magic item approach really bothers me, and that is attunement. I don’t hate the idea of attunement; in fact, I like it quite a bit. But the implementation of it in the game is, in a word, inelegant.
That’s a shame, because I think attunement could have been a fantastic new feature of the game rather than just an arbitrary power cap. Let me put it this way. As a GM I never want to be in the following situation: