River+orcs

[littlebrather]

                 #######   #####################
                 #.....#   #...../.............#     ##
                 #.<...#   #.....#####.........######=#o
                 #.....#   #.....#   #.........======o===
                 ###.###   #######   #####/###=====@=====
                   #.#               #####.##========o===
               #####.#####    ########=========########o
               ===========  !==....===========##
               ===========  =====#===========##
               ===========  ==========.....###
               #####/##########====#.......#
               #......./.........=./.......#
               #.......#############.......#
                ..........        .........#
                .......###        ##########
                 ....../
                   #####

Wow,It was the first time I got something like this...
I was pretty sure that river shouldn't destroy the walls of the vault O_o

[Dudley]

                 #######   #####################
                 #.....#   #...../.............#     ##
                 #.<...#   #.....#####.........######=#o
                 #.....#   #.....#   #.........======o===
                 ###.###   #######   #####/###=====@=====
                   #.#               #####.##========o===
               #####.#####    ########=========########o
               ===========  !==....===========##
               ===========  =====#===========##
               ===========  ==========.....###
               #####/##########====#.......#
               #......./.........=./.......#
               #.......#############.......#
                ..........        .........#
                .......###        ##########
                 ....../
                   #####

Wow,It was the first time I got something like this...
I was pretty sure that river shouldn't destroy the walls of the vault O_o

Only tension rooms are superior to water, iirc

[Silfir]

Monsters and traps are superior to water too. So the vault's walls and floor will be penetrated by the river, but the monsters will turn river squares into floor.

[Aielyn]

Items generated at level creation are also superior to water. I had a potion of water generated in the middle of a river in my current game, and although I was worried that it was an underwater potion (which would be that colour irrespective of the type of item), requiring me to swim for it, it turned out it was on its own little island, so I could teleport to it safely.

EDIT: Oh, and just because it hasn't been said, yet - stairs are also superior to water.

[Sian]

Herbs are superior as well ...

almost everything but normal rooms are superior

[Deg]

Herbs are superior as well ...

almost everything but normal rooms are superior

I don't think all special rooms are superior. I mean a trap room can be cut off for example.

[Sian]

'almost' is the operative word.