Ring of sustenance
Not to be confused with the ring of sustain abilities.
A ring of sustenance reduces the total satiation cost of your actions by 40%. It is stackable, but the benefits decline with multiple rings (ie, an additional 24% for the second ring, an additional 15% for the third). The resultant hunger rate is always rounded down. Thus, for most races, who hunger at a rate of 3 nutrition/turn, one ring of sustenance will reduce that rate to 1 nutrition/turn.
new_hunger_rate = old_hunger_rate × (6/10)^(#_of_rings_of_sustenance)
Rings of sustenance cannot reduce satiation costs below 1 per turn. They are cursed 2% of the time.
Many players malign these rings, as they provide no benefit other than reducing food consumption, and there is usually enough food available for even a 15-rune ascension. However, they can actually serve several purposes:
- They are useful for low-strength races because they reduce the amount of food one has to carry around. In particular, this can allow a low-strength player to carry more useful items (such as potions of heal wounds or multiple attack wands) in corpseless branches such as Pandemonium or the Abyss.
- The reduced hunger rate can allow a player to cast spells earlier than the hunger cost would normally let them, since they will be consuming less food overall.
- These rings can be a godsend (pun intended) for those whose god takes sacrifices: Trog, Okawaru, Makhleb, and to a lesser extent Nemelex and Fedhas. Since you won't have to chop up every other corpse you come upon for food, you will gain piety considerably more quickly.
- High-hunger races such as trolls will find these rings very useful in general.
- The temporary wearing of one during long intra-dungeon journeys through empty levels or branches is a particularly frugal way to conserve permafood.
As compared to an amulet of the gourmand
An amulet of the gourmand fulfills many of the same roles as a ring of sustenance, and many players would argue that it is a better item. It definitely has distinct advantages and disadvantages when compared to a ring of sustenance.
Its advantages are:
- It is generally superior in corpse-filled branches. Being able to gorge yourself on every passing centaur usually proves superior to simply having hunger reduced by 2/3. In particular, it is better for mitigating spell hunger, as long as there are creatures nearby.
- Properly used, an amulet of the gourmand should allow you to gain piety with a blood god even more quickly than a ring of sustenance.
However, in some ways a ring of sustenance is superior:
- An amulet of the gourmand must be actively used (by eating corpses) to provide any benefit, whereas the effect of a ring of sustenance is entirely passive. At the very least this makes the amulet more tedious to use; for many players, it can mean less overall benefit.
- The amulet is of no help in corpseless branches.
- The amulet slot may be more valuable in certain situations. For example, an amulet of resist mutation is extremely useful while exploring the Slime Pits.
Rings of sustenance were retired in 0.15.
In older versions, rings of sustenance merely reduced food consumption by 2/turn, to a minimum of 1. This made these rings less useful to high-metabolism characters, since their food consumption would be proportionally reduced much less.