Sokoban Level 2b

Sokoban Level 2b is one of the two standard maps for the second level of Sokoban in NetHack. It is also among the various possible maps for that level in variants of NetHack; in Hack'EM, the map is named "Squared Off". There are 20 boulders and 15 holes, leaving 5 spare boulders.

-----------       ----------- 0 boulder
|....|....---     |.........| ^ hole
|..00|00...@|     |.........| @ starting position/downstairs
|.....0...---     |.........| < upstairs
|....|....|       |....<....|
|-.---------      |.........|
|..0.|.....|      |.........|
|.00.|0.0.0|      |.........|
|..0.....0.|      |.........|
|.000|0..0.----------------+|
|....|..0.0.^^^^^^^^^^^^^^^.|
-----------------------------

Strategy

The following solution solves the level without putting any boulders in an immobile position. Faster solutions which do not necessarily leave every boulder free might exist. You can watch a TTYREC video of this solution or a YouTube video.

All boulders are replaced by letters so they can be referred to. Moving the boulders is shortened to r for right, l for left, u for up, d for down. An asterisk is used to denote the last move filled a hole (and thus removed the boulder from the game). So Nddrr* means move boulder N two times down and two times to the right into a hole.

Make way to the fourth room (lower right) by storing boulders in earlier rooms. It is not necessary to store as many boulders as in this example:

-----------       ----------- E lllr rrrr u
|....|....---     |.........| G uuuu u
|..AB|CD...@|     |.........| N uuuu uur
|.....E...---     |.........| L rrrr r
|....|....|       |....<....|
|-.---------      |.........|
|..F.|.....|      |.........|
|.GH.|I.J.K|      |.........|
|..L.....M.|      |.........|
|.NOP|Q..R.----------------+|
|....|..S.T.^^^^^^^^^^^^^^^.|
-----------------------------

Clear the 4th room with the exception of I and Q:

-----------       ----------- R r
|....|....---     |.........| T rr*
|.GAB|CDE..>|     |.........| S rrrr r*
|..N......---     |.........| M ddrr rrr*
|....|....|       |....<....| R drrr rr*
|-.---------      |.........| K dddr rrrr r*
|..F.|.....|      |.........| L rrdd rrrr rrr*
|..H.|I.J.K|      |.........| J dddr rrrr rrrr r*
|......@LM.|      |.........|
|..OP|Q..R.----------------+|
|....|..S.T.^^^^^^^^^^^^^^^.|
-----------------------------

Clear the 3rd room (lower left) with the exception of F:

-----------       ----------- O urrr rrrr ddrr rrrr rrr*
|....|....---     |.........| P urrr rrrd drrr rrrr rrr*
|.GAB|CDE..>|     |.........| H ldrr rrrr rrdd rrrr rrrr rrr*
|..N......---     |.........|
|....|....|       |....<....|
|-.---------      |.........|
|..F.|.....|      |.........|
|..H.|I....|      |.........|
|..........|      |.........|
|..OP|Q....----------------+|
|....|.............^^^^^^^^.|
-----------------------------

Clear the 2nd room (upper left) with the exception of B, and finish off with the two boulders from the 4th room.:

-----------       ----------- G dddd ddrr rrrr rrdd rrrr rrrr rrrr*
|....|....---     |.........| N lddd ddrr rrrr rrdd rrrr rrrr rrrr r*
|.GAB|CDE..>|     |.........| A ddld dddr rrrr rrrd drrr rrrr rrrr rrr*
|..N......---     |.........| Q ulll rrrr rrrd drrr rrrr rrrr rrrr*
|....|....|       |....<....| I dlll rrrr rrrd drrr rrrr rrrr rrrr r*
|-.---------      |.........|
|..F.|.....|      |.........|
|.@..|I....|      |.........|
|..........|      |.........|
|....|Q....----------------+|
|....|................^^^^^.|
-----------------------------

The level is now finished:

-----------       -----------
|....|....---     |.........|
|...B|CDE..>|     |.........|
|.........---     |.........|
|....|....|       |....<....|
|-.---------      |.........|
|..F.|.....|      |.........|
|....|.....|      |.........|
|..........|      |.........|
|....|.....----------------+|
|....|.....................@|
-----------------------------

Next level

After this level, you will face either of the following levels:

Sokoban Level 3a -------- ---.|....| |...0....|---------- |.-.00-00|.|.......| |.00-......|.......| |.-..0.|...|.......| |....-0--0-|...<...| |..00..0...|.......| |.--...|...|.......| |....-0|---|.......| ---..0.-----------+| |..0@^^^^^^^^^^^.| ------------------

Sokoban Level 3b -------------------- |........|...|.....| |.00..-00|.-.|.....| |..|.0.0.|00.|.....| |-.|..-..|.-.|..<..| |...--.......|.....| |...|.0.-...-|.....| |.0.|0.|...--|.....| |-0.|..-----------+| |..0....^^^^^^^^^^.| |...|.@------------- --------