Boulder

A boulder is a huge stone, represented by an '. They can be used to block corridors, doorways and pits. Boulders are especially useful for crossing water: push them into water and they will create new dry land for you to walk. Giants may also pick the up and throw them - no other monster is strong enough to do that.

Boulders are sometimes found in traps, where there is a hidden switch that triggers a rolling boulder, that may crush the player. They can also be summoned by using a scroll of earth. To get past a boulder, the player may break it into stones with a pickaxe, wand of striking or force bolt. It is also possible to drop every item from the inventory and squeeze past it.

A spell of stone to flesh turns a boulder into a huge chunk of meat.

Tactics for pushing boulders

Four of the boulders in this screenshot were blocking the long corridor, but through deft squeezing and pushing the hero pushed them into rooms. If that boulder in the lower-right had started at that position, it would likely be part of a boulder trap.

If you push a boulder, then it will move to the opposite square. In the diagrams below, the # represents where the boulder will move. (Boulders in Sokoban never move diagonally.)

@     @     @       #     #     #
 `    `    `   #`@   `    `    `   @`#
  .   .   #           @   @   @

If there is no space or if it is occupied a monster (being hostile, peaceful, or your pet) then you cannot move the boulder in that direction. However, if your inventory is completely empty, you can squeeze onto the square containing the boulder. (The fastest way to drop your inventory is to press D and then choose option "A" to drop all items.) Such squeezing is useful if there is a door, hidden space, or boulder on the other side.

If a monster blocks the other side and will not move away, you have the option of squeezing onto the boulder and fighting it bare-handed and naked, or you can throw ammunition past the boulder. The player below might want to toss darts, rocks, or other objects at whatever is blocking the way to some holes ^ in Sokoban.

------------
..@`I^^^^^..
------------

You can move diagonally around boulders (but not in Sokoban). So the following boulder does not block your path provided that you know how to use [yubn] or numpad to move diagonally:

  #
  #
##`##

If a boulder is blocking a corridor, and if you are able to push it into a room or into a position like the above, then you can walk around it.

When faced with two consecutive boulders in a corridor, as shown below, you can squeeze past one to push the other.

##@``###

##*@`###

##*`@`##

##*`#@`#

However, wandering around naked with no wielded weapon, or allowing hostile monster to take from your inventory, might put you in too much danger. You might want to push the other boulder and retrieve your inventory quickly. (The fastest way to retrieve the inventory is to press @ to toggle autopickup on and then move onto the square where you dropped it. Then you might want to press @ again to toggle autopickup off.)

Boulders, like anything else, cannot pass diagonally through open doors. If you need to do that, destroy the door by closing it with c and then kicking it down with Control-D.

The two boulders below are stuck against a wall, and you may only push them in two directions:

-----------          ------
|...`.....|          |....|    -------
|.........|     #####..`...####......|
|.........|     #    ------    |.....|
---.-------   ###              -------

If a boulder becomes stuck in a corner, then you can not move it at all, even if you squeeze onto its square (unless you are able to dig around it). In Sokoban, a 2x2 square of four boulders (or a 2x2 square of both boulders and walls) is almost likewise stuck, but you might be able to squeeze yourself to free the boulders. (Squeezing causes a luck penalty in Sokoban.) Outside of Sokoban you could have freed a boulder by moving it diagonally, but not if you have two boulders stuck against the same wall.

----     ----     ......     ...|..  
|`..     .``.     ..``..     ---`..
|...     ....     ..``..     ..``..
                  ......     ......

    stuck         stuck in Sokoban

Be very careful in Sokoban to not stick boulders in the above manners unless you are able to solve the level with the remaining boulders.