After successful completion of an 8 hour rest, you have the opportunity to regain more HP than normal, by using the hit die system from Dungeons & Dragons 5th Ed. The first thing that happens at the end of the rest, is you spend your hit die. For each hit die you roll, you add your CON modifier and regain that much HP to a minimum of 1. You can roll none, some, or all of your hit die.
After regaining HP, you regain some of your hit die. You gain half your total number, rounded down, to a minimum of one, and you cannot exceed your maximum. For example, a 7th level character may have had 7 hit die when they ended their rest and chose to spend 2, leaving a total of 5. They would then regain 3 hit die as that is half of 7 rounded down, however because that would give them a total of 8, they would only regain 2, to their maximum of 7.
In terms of Ability Score damage, each Ability Score still only recovers 1 point for an entire 8 hour rest, however you may choose to expend hit die to recover an additional point to every Score in lieu of rolling it for HP. You may mix and match spending hit die for HP and Ability Score recovery.
If you do not successfully complete a rest on the first try, you can try again within the same 24 hour period, however you cannot gain the benefits of a successful 8 hour rest more than once a day. If you do not get at least 6 hours of rest, you will be fatigued but only require 6 hours of rest in the future to lose fatigued. If you are already fatigued and do not get at least 6 hours of rest, you become exhausted.
Sleeping in Heavy Armor causes fatigue, but Leather and Medium armors incur no penalty. If a character is ambushed without their armor on, donning is much hastier. Leather Armor requires a Swift Action, Medium requires a Move Action, and Heavy requires a Full Round Action.
Elves and Gnomes are descended from Feyfolk and only require a 4 hour trance to gain the benefits of an 8 hour rest. They may sleep as normal if they’d prefer, though there is no benefit from doing so.
Time will be tracked more diligently than in most campaigns. Days will pass into months, and the different constellations may cause different things to happen or cause things to behave in certain ways that wouldn’t during other months. The months will pass into seasons which will have a greater effect to events and behaviors and will even affect terrain when appropriate, and seasons will pass into years and the passing of time will have a lasting impact on the world. Towns will grow, countries will become stronger, and villains will grow more powerful.
Just like in real life, the effects won’t always be immediately obvious but there will be consequences to the choices players make as they choose to engage in certain things and ignore others. PCs and NPCs will age over time to give a sense of real experience and accomplishment, and excessive downtime and time spent travelling will cause a noticeable passage of time in game just like adventuring.
See the gods and astrology section for more information on the specifics of months and seasons.
Keeping track of material components slows the game down, so all spell casters may act as if they had Eschew Materials. As compensation, Sorcerers and Bloodragers may take one of their Bonus Feats that they otherwise meet the requirements for in place of Eschew Materials.