# Ring of polymorph

=

Name

polymorph

Appearance

random

Base price

300 zm

Weight

3

Probability out of rings

3.57%

Probability out of items in:

containers

Rogue level

Gehennom

Elsewhere

0.179%

0.179%

0.286%

0.107%

A ring of polymorph is a ring that appears in NetHack. When worn, it causes you to polymorph at random intervals.

Contents

1 Generation
2 Description
3 Strategy

3.1 Identification

4 History
5 Messages
6 Variants
7 References

Generation
90% of rings of polymorph randomly generated in the dungeon are cursed, with the remaining 10% being uncursed.
Wizards may have a ring of polymorph as one of the random rings in their starting inventory, though they will never start with a means of polymorphing and a ring of polymorph control simultaneously.[1]

Description
Wearing a ring of polymorph gives you polymorphitis, which has a 1% chance of polymorphing you each turn: this polymorph can also fail and induce system shock unless you have polymorph control, or else are wearing dragon scales or dragon scale mail. Eating the ring has a 1⁄3 chance of giving you intrinsic polymorphitis. Monsters will never wear this ring - any monster that randomly polymorphs constantly is usually a shapechanger such as a chameleon.
If you have polymorph control, you may choose the form you change into whenever the ring would polymorph you. If you are afflicted with lycanthropy, the ring of polymorph will instead trigger a change from your normal form into the animal form of the werecreature that infected you, or vice versa; polymorph control will prompt you with the option to accept or decline the change. If you are wearing an amulet of unchanging, the ring of polymorph will have no effect beyond ring hunger.
Dropping the ring into a sink will turn the sink into an altar (of random alignment), a fountain, a grave, or a throne, with an equal probability of each (25%).[2]

Strategy
The ring of polymorph is one of several reasons that wearing unidentified rings randomly is a Bad Idea: even when uncursed, wearing one for any extended period of time may result in you shifting into a form that removes or breaks armor, has low carrying capacity or (worse yet) leaves you with no hands to remove the ring. However, if you have an uncursed ring to pair with a ring of polymorph control, you can use these intermittent transformations to your advantage in order to obtain powerful monster forms for various purposes. See the strategy section on the polymorph control article for the various forms you can take.
Players who have not yet discovered a wand of polymorph or else wish to reserve wand charges for polypiling can make use of both rings, saving polymorph traps for pets if they wish. For cautious players, controlled polymorphing using these rings can be reserved for specific circumstances, such as while locked within a co-aligned temple with a stash.

Identification
Main article: Price identification
Informally identifying the ring of polymorph can be fairly difficult - wear-testing is very risky compared to other price-identified 300zm rings, as an especially unlucky player may find themselves quickly polymorphed with their valuable armor broken. While it is more likely to be cursed than other rings priced at 300 zm, this is by no means guaranteed.
In addition to ruling out the ring of conflict by wearing the ring near relatively weak and/or peaceful monsters, you can also rule out the ring of teleport control&nbsp;using a teleportation trap.
The odds of a ring that is price-identified and tested for beatitude being a ring of polymorph is given in the following table:

Testing done
Any BUC
Non-cursed
Uncursed
Cursed
Blessed

Any price
3.45%
0.50%
0.52%
10.14%
0%

300 zm
25.0%
3.6%
3.6%
75.0%
--

300 zm, not telecontrol nor conflict
50.0%
10.0%
10.0%
90.0%
--

History
The ring of polymorph first appears in NetHack 2.2a along with the ring of polymorph control.
The effect of dropping the ring down a sink is introduced in NetHack 3.6.0, and was integrated from UnNetHack. In NetHack 3.4.3 and previous versions, including some other variants based on those versions, the game will instead print a message with no other effect:

The sink looks momentarily like a fountain.
Messages
The sink transforms into a 

<feature>!
You dropped a ring of polymorph down a sink, turning it into a different dungeon feature, and you are not blind.[2]
Variants
Many variants often add new dungeon features, including ones that a sink also can be transformed into by dropping a ring down one; the probability of a sink turning into a given dungeon feature remains equal for each one.

References

↑ src/u_init.c in NetHack 3.6.7, line 998

↑ 2.0 2.1 src/do.c in NetHack 3.6.7, line 321

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