So my gaming community i'm a part of is starting a RP server, and I was going to make an inn before realizing they were pretty much useless since sleep wasn't required. So, mainly for RP servers, I thought it'd be cool if there was a mod that required players to sleep in a bed every so often or they'd start to slowly take damage, sort of like starving, though it would go down slower of course.
This would of course require it to be doable on multiplayer servers where not everyone is going to sleep at the same time. I'd think you'd just have a meter like with food that would go down entirely maybe once every two days or something. I was surprised there wasn't already a mod like this when I looked.