Here’s some technical information on the game HyperRogue that I collected from the game’s source code which isn’t otherwise documented as far as I am aware.
Which types of walls do and do not conduct electricity is counter-intuitive, at least to me.
These (and only these) wall types are conductive:
• Sandstone, dead troll (“Dead Rock Troll”), dead troll 2 (“Dead Troll”), big tree, small tree, barrel, red rock, vine, metal wall, and slime.
Consequently, killing a Dark Troll always leaves a non-conductive wall, but killing any other type of troll always leaves a conductive one.
Table of which orbs can appear in which lands: [PDF] [OpenOffice]
Local & global rarities for all the orbs: [CSV] [gnumeric]
Rarities of guest orbs: [CSV] [gnumeric]
These uses the internal names for all the lands and orbs, which don’t always match the display names, but you should be able to figure out the correspondence easily — except for Dual/OrbSide2, which is Crystal World and Orb of the Triangle.