So, I'm running a Pathfinder game with 6 characters. Of those 6, 4 of them are wearing rings of Sustenance. Two of those are casters. My question is, how does the Ring of Sustenance interact with daily-refreshing powers? It says that 2 hours of sleep are equivalent to 8 hours, even for spellcasting.
Now, for Rage, it states "The total number of rounds of rage per day is renewed after resting for 8 hours, although these hours do not need to be consecutive." Does that mean the Barbarian still requires 8 hours of twiddling his thumbs? It says something similar for the Monk's Ki Pool: "The ki pool is replenished each morning after 8 hours of rest or meditation; these hours do not need to be consecutive."