Rest is a device that allows more casual gamers to stay somewhat on par with other players, as to character level. It's also a clever device to encourage less-active players to keep their accounts, making players want to come back and play some more after some time away from the game.
Storing up rest
Resting...
While in an inn or anywhere in a capital city, your player portrait will begin to glow and your level circle will say zzz, indicating that you are resting. If you log off here, you will continue to rest while offline.
With only one character in your account, one bubble (5% of a level) of rested XP is earned for every 8 hours spent resting, up to a maximum of 30 bubbles, 150% of a level. In other words, you can leave your character resting in an inn or capital city for up to 10 days (without playing) before you earn the maximum amount of rest state. A resting character stores up one full level of rest every 160 hours (6.67 days).
If there are more characters in your account, the amount of rest XP actually gained is less than 5% per 8 hours.[citation needed] Otherwise it would be possible to have many characters and play each in turn with fully rested XP. The rest XP penalty isn't very large, but large enough to prevent abuse. Having a few extra characters in your account doesn't hurt.
You also become rested while logged off in the wilderness, but only at one-fourth the normal rate. Be sure to log off in an inn whenever possible. The rest zone actually extends some distance outside rural inns, so if for some reason you want to log off outside the inn proper, watch your character icon for the "zzz."
It may be also possible to engage the resting state while in ghost form, or dead.
Consuming rest
Rest mark
When rested, your XP bar will turn blue, and a notch will appear indicating exactly how rested you are. You will earn double XP from killing monsters while rested until your XP bar fills to the notch. A rested character earns double combat XP until this rest state is consumed, at which point the message
- You feel normal.
appears and you resume normal XP gains for kills.
When you are rested, when you kill a monster, in the combat log it may say something like
- 120 XP (+60 rested XP).
In this case, you did not get 180 XP. Your total experience was 120, half of which was a rested bonus. Unrested, that kill would have yielded 60 XP.
A note on consuming rested XP: Let's say you had 5000 rested XP. You get 120 XP for killing a mob. You now have 4880 rested XP left, not 4940. That extra XP that you got "(+60 rested XP)" was not the only XP pulled from your rested XP pool.
Non-combat experience such as exploration and quest experience does not consume rest state. The rest marker will be moved forward by as many XP as you gain from the exploration or quest.
Further information
When you are about 5th or 6th level, you will recieve quests to go to another town area. This town is where the first inn is available to a new character. Put another way, until you get your first 5 or 6 quests out of the way you will not happen across an inn and so you will have to 'camp out' when you logout. It is easy enough to get these first five levels, so it is good to finish those quests and hurry over to the inn.
At this inn, and at all other inns that you find, you will find an innkeeper. When you speak to him you can bind your 
[Hearthstone] to that inn. When you activate your hearthstone you will find yourself at that inn. This is effective when you are in the field, and you must suddenly log out. In this case you can activate your hearthstone, and log out, and there at the inn you will gain rest.
- Also see
- [Hearthstone]
- Resting at the Official site.
- RestedBonus, a UI modification that tracks rest bonuses.