View source for Vibrating square

{{todo|Is the article sufficiently updated to reflect the strategic implications of teleporting onto the vibrating square as of 3.6.2, as well as monsters no longer avoiding it?}} 
{{level|Vibrating square level
 |from=19|to=23
 |branch=Gehennom
 |digfloor=no
 |digwalls=yes
 |bones=no
 |mapping=yes
 |teleport=yes
}}
The '''vibrating square''' is the [[square]] where the [[invocation ritual]] is to be performed for entry into [[Moloch's Sanctum]]. The square, once found, is automatically marked with a special map glyph {{magenta|~}}.

==Generation==
It is always located on the penultimate [[dungeon level]] of [[Gehennom]], which could be between levels 44 and 52. It is the lowest level that can be reached without performing the ritual; until the ritual is performed, there is no [[staircase]] leading down from that level. Only the [[Sanctum]] level has a higher dungeon level number.

The level with the vibrating square is in most other respects an ordinary maze level of Gehennom.

==Identification==
Confirm you are on the vibrating square level by checking that the floor is undiggable then read a scroll of [[gold detection]] while [[confused]] to quickly locate the vibrating square. You can also use a [[crystal ball]]. You must specify {{white|^}} to search for traps; specifying {{white|~}} will search for [[Long worm|long worms]] instead.

Another way to locate the vibrating square is to move over it, at which point you will get the message: "You feel a strange vibration under your <feet>.", or "You feel a strange vibration beneath you" if you are flying or levitating. This message will always occur if you walk on top of the vibrating square or jump (or hurtle) over it, but not if you are carried over it by an engulfing monster. There are no other special features of the square.

The vibrating square cannot appear near the edge of the screen nor the [[staircase]], because there must always be room for the ring of [[fire trap]]s and [[moat]]s to appear around it.{{refsrc|mkmaze.c|587}} Specifically, it will be at least five squares from the left and right sides of the map, at least four squares from the top or bottom, and not within a 23&times;23 square area centered on the upstair. It will also not be in a straight line with the upstair or on the same square as a trap, although it may be on the same square as a boulder or other item.

In this example map, the eligible places are marked with ({{green|X}}). Red spots are too close to the edge, blue ones in line with the stairs, and yellow ones too close to the upstairs. You can mouse over the map to see what is wrong with some of the squares.
<div class='ttyscreen'><replacecharsblock rules="ttymap">
r=<span class="nhsym clr-orange" title="Too close to the side">.</span>
l=<span class="nhsym clr-brightblue" title="In line with the stairs">.</span>
d=<span class="nhsym clr-yellow" title="Too close to the stairs">.</span>
g=<span class="nhsym clr-green" title="Possible location">X</span>

 ----------------------------------------------------------------------------- 
 |rrrrrrr|rrrrrrrrrrrrrrr|rrrrrrrrrrrdddddldddddl|d|ddl|ddddrrr|rrrrrrrrr|rrr| 
 |r-----r|r-----------r---r-----r-----d---d-----l|d|d|d|d|d---r|r|r-----r---r| 
 |r|rrrrr|rrr|rrrrrrr|rrrrr|rrr|rrr|rdd|d|d|ldd|ldd|l|ddd|d|r|r|r|rrr|r|rrr|r| 
 |r---g---g---g-----g---g---g|g-----g--|d|d|d|d|--d|d----|d|g|g|g|--g|g---r|r| 
 |rrr|g|ggg|ggg|g|g|ggg|g|ggg|ggggggg|d|ddd|d|l|ldl|ddd|d|d|ggg|g|g|g|gggrrrr| 
 |r|r---g---g---g|g---g|g|g-----------d|d---d|d-------d|d|d|----g|g|g-------r| 
 |l|lllll|lll|lll|lll|l|l|l|lllllll|lllll|lll|ll<|lllll|l|l|lllll|l|lllllll|l| 
 |-------|g---g---g--|g--|g|g-----g|g-----d-----l|d-----d|d|g-----g|------r--| 
 |rrr|ggg|g|ggg|ggggg|ggg|ggggggg|g|g|ddddd|d|ldl|ldddddd|ddg|ggggg|g|ggg|rrr| 
 |r|r|g|g|g|g-------g---g|------g|g|--d-----d|d---------d-----g---g|g|g|g---r| 
 |r|rrg|ggg|g|ggggg|ggg|g|ggggg|g|g|gdd|ddddl|ddldddldddddd|ggggg|ggg|g|grrrr| 
 |r|------g|g---g|g|g|g|g|g---g|g|g|g|d|d---d-------------d-----g|--g|g|----r| 
 |r|rrggggg|ggg|g|ggg|g|ggg|g|g|g|ggg|ddd|ldddd|ldddddl|d|ddggggg|ggg|g|grr|r| 
 |r-----------g|g|----g-----g|g|----g|--------d|l-----d|d|d-----g|----g|g|r|r| 
 |rrr|rrrrrrr|r|r|rrrrrrr|rrr|r|rrr|r|ddldd|ddd|ldd|ddd|ldd|rrr|r|rrrrr|r|r|r| 
 |r|r|r---r---r|r---------r|r|r|r|r---d---d-------d|d-------r|r---r-----r---r| 
 |r|rrrrr|rrrrr|rrrrrrrrrrr|rrrrr|rrrdl|ddddddddldd|ddddddldr|rrrrr|rrrrrrrrr| 
 ----------------------------------------------------------------------------- 

</replacecharsblock>
</div>

==History==
In [[NetHack 3.4.3]] and older versions, the vibrating square was not marked on the map, and it could not be sensed when jumping or hurtling over it.

In [[NetHack 3.6.0]], the vibrating square was marked with {{yellow|^}}.

In [[NetHack 3.6.3]] and older versions, the player could not [[teleport]] directly onto the vibrating square, and monsters would also avoid it.

==Variants==
===SLASH'EM===
In [[SLASH'EM]], the level with the vibrating square can have various types of borders instead of walls: clouds, lava, water, ice, or, worst of all, nearly indestructible iron bars. If you get any type of borders other than walls or iron bars, it is generally easier to scan the whole level line-by-line while levitating for the vibrating square. This is not quicker in game turns, since you are walking over more squares, and a careful speedrunner will still want to scan for the vibrating square normally.

In the case of clouds and ice, however, this will not work. The vibrating square can be placed on one ice and cloud squares, presumably since they can be walked over, and the whole eligible region of the level must be searched, not just the "path." If the vibrating square is made of ice, this can be melted as usual, leaving the square underwater.

===SporkHack===
In [[SporkHack]], the vibrating square is marked by a lit [[brazier]].

===UnNetHack===
In [[UnNetHack]], the character will start feeling vibrations when they step within two tiles of the square, regardless of intervening walls, making the search process much easier.

==References==
<references/>
{{nethack-364}}
[[Category:Dungeon features]]