Sokoban Level 2b

Although this Sokoban level has the most boulders, it is not very hard. There are 20 boulders and 16 holes.

0 boulder
^ hole
@ starting position/downstairs
< upstairs

-----------       -----------
|....|....---     |.........|
|..00|00...@|     |.........|
|.....0...---     |.........|
|....|....|       |....<....|
|-.---------      |.........|
|..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 video of this solution.

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....^^^^^^^^^^.| |...|.@------------- --------