Ring of polymorph control
A ring of polymorph control is a type of ring that appears in NetHack. The default randomized appearance associated with it is "an emerald ring".[1]
Contents
Generation
Wizards may be given a ring of polymorph control as one of the two random rings in their starting inventory, though they will never start with the ring and a means of polymorph simultaneously.[2][3][4]
General stores and jewelers shops can sell rings of polymorph control.
Description
Wearing a ring of polymorph control grants extrinsic polymorph control: whenever a hero with the property is polymorphed for any reason, if they are not stunned or unconscious and there is no applicable special case (e.g. polymorphing while wearing dragon scales or dragon scale mail), the player will be prompted for the form of the monster they wish to change the hero into. A hero with the ring worn will also never suffer system shock when polymorphing, though there is still a 1⁄5 chance of polymorphing into their own species each time they polymorph, regardless of what monster form they choose.
Eating the ring has a 1⁄3 chance of successfully absorbing its magic and granting intrinsic polymorph control.
If a hero has lycanthropy and would change between forms while wearing the ring, the player is given a prompt asking if they wish to do so; declining will leave the hero in their current form.
Strategy
Controlled polymorph has a nearly endless amount of applications for players, from eating jewelry to obtaining otherwise-difficult pets, to obtaining certain intrinsics and making travel easier, to gaining an edge in fights and overpowering otherwise-difficult hostile monsters. This makes the ring of polymorph control a valuable tool in almost any player's kit, and thus a tempting target for a wish.
In the early game, if you have no other means of protecting yourself from unseen polymorph traps in the lower dungeon, the ring can be a sufficient substitute - you can at least control the outcome of most unexpected polymorphs, preserving your armor and avoiding system shocks in the process. Unfortunately, there is still the chance of a same-race polymorph occurring, which can come with undesired adjustments to your experience level or attributes.
Monks in particular may seek out a ring of polymorph control to avoid the severe to-hit penalties for wearing armor, which are only applied to their base form, and can also make use of monster forms with multiple good attacks to complement their martial arts skill.
Identification
Though the ring of polymorph control is one of the safer 300zm rings, it shares a base price with the ring of polymorph: this makes it difficult to actually test for the former ring due to the dangers of random, uncontrolled polymorph - though it is much less likely to be cursed than a ring of polymorph on average, this is not reliable enough to be worth the risk for more cautious players.
If you are willing to take the risk, you can wear-test to rule out the ring of teleport control by putting it on and then activating a teleportation trap on or close to your square; you can rule out the ring of conflict by wearing it in sight of monsters that are near each other (e.g. a pet and almost any other monster). Testing rings for polymorph control becomes much safer and easier once you have the ring of polymorph formally identified.
The odds of a ring that is price-identified and tested for beatitude being a ring of polymorph control is given in the following table:
| Testing done | Any BUC | Non-cursed | Uncursed | Cursed | Blessed |
|---|---|---|---|---|---|
| Any price | 3.45% | 4.47% | 4.69% | 1.13% | 0% |
| 300 zm | 25.0% | 32.1% | 32.1% | 8.3% | -- |
| 300 zm, not telecontrol nor conflict | 50.0% | 90.0% | 90.0% | 10.0% | -- |
History
The ring of polymorph control first appears in NetHack 2.2a along with the ring of polymorph.
Messages
- The sink momentarily looks like a regularly erupting geyser.
- You dropped a ring of polymorph control down a sink, and you are not blind.
Variants
SLASH'EM
In SLASH'EM, the ring of polymorph control is an even more enticing wish target for many players due to the higher amount of powerful and useful monster forms available such as the crystal golem or giant shoggoth.
The ring of polymorph control is a special goal for Doppelganger and lycanthrope players: a doppelganger that finds one before they get the intrinsic at experience level 9 can access the better monster forms much earlier, while a lycanthrope that finds the ring gains control over their otherwise-random transformation and can employ their innate abilities more strategically.
SpliceHack
In SpliceHack, a ring of polymorph control can be created by combining a ring of polymorph with a ring of teleport control at a furnace.
SlashTHEM
In SlashTHEM, the details from SLASH'EM still apply with one important exception: doppelgangers now gain intrinsic polymorph control at XL 25, requiring them to keep track of monsters they have eaten or grown strong enough to shift into. This makes an extrinsic source of polymorph control more useful throughout the game and all the more enticing for them. In addition, several new monsters are available that may prove to be useful polyforms.
