# Sokoban Level 1i

Sokoban Level 1i is a new possible map for Sokoban that appears in UnNetHack and Hack'EM. In Hack'EM, the level map is named "Open the Door". It has 8 boulders and 7 pits, leaving 1 spare boulder.

In UnNetHack, this level may be flipped horizontally or vertically like all Sokoban levels.

```       -----------  0 boulder
|.........|  ^ pit
|....0.0..|  > starting position/downstairs
------ |.0.-----.|  < upstairs
|....-----.0..--0|  ? scroll of earth
|.......0.0......|  # iron bars
|-^|.......--.--.|
|-^|--->----|.||.|
|?.------...|.--.--
|?..^^^^^.<.#.0...|
---------...|.....|
-----------
```

## Strategy

The following solution may not be very fast or organized. Improvements welcome. Like all Sokoban levels it can be solved without making any boulders 'stick'.

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 pit (and thus removed the boulder from the game). So "N ddrr*" means move boulder N two times down and two times to the right into a pit.

First, push the two nearest boulders into the pits:

```       -----------  F llll lld*
|.........|  G rrrr llll llll llll dd*
|....A.B..|
------ |.C.-----.|
|....-----.D..--E|
|.......F.G......|
|-^|.......--.--.|
|-^|---@----|.||.|
|?.------...|.--.--
|?..^^^^^.<.#.H...|
---------...|.....|
-----------
```

Pick up the two scrolls of earth and push the next few boulders into the pits:

```       -----------  D r
|.........|  C rddl llll llld dddr r*
|....A.B..|  A lldd dlll llll lddd drrr*
------ |.C.-----.|  B llll dddl llll llld dddr rrr*
|....-----.D..--E|
|................|
|-@|.......--.--.|
|-.|--->----|.||.|
|?.------...|.--.--
|?..^^^^^.<.#.H...|
---------...|.....|
-----------
```

Solve the last two boulders:

```       -----------  D lluu dddl llll llld dddr rrrr*
|.........|  H luuu ulll llll llll dddd rrrr rr*
|.........|
------ |...-----.|
|....-----..D.--E|
|................|
|-.|.......--.--.|
|-.|--->----|.||.|
|..------...|.--.--
|....@.^^.<.#.H...|
---------...|.....|
-----------
```

The level is now complete. Check under the last boulder in case an item happens to be underneath:

```       -----------
|.........|
|.........|
------ |...-----.|
|....-----....--E|
|................|
|-.|.......--.--.|
|-.|--->----|.||.|
|..------...|.--.--
|......@..<.#.....|
---------...|.....|
-----------
```

## Next level

### UnNetHack

UnNetHack's Sokoban branch has only three levels per game, collapsing the 'second' levels into the first floor, so the first level leads straight to the pool of third levels: