adnd-1emapspublished-adventures
Looking at the map for area A and area C of I1 Dwellers of the Forbidden City, there are several markings that are not on the legend for the map. In each case, a corridor is interrupted by a zigzag connected to a small oval with a number and a tick mark, like an apostrophe. At first, I thought they were chasms with the depth indicated, but this doesn't seem to be referenced anywhere in the module.
Can anyone identify these markings?
Here are some original old school D&D modules that should be easy to find and not cost you an arm or a leg if you buy them online:
I1 The Forbidden City (TSR, 1980): Old school AD&D sandbox setting in a "lost" jungle city inhabited by snakemen (yuan ti), frogmen (bullywugs), and lots of other weird and dangerous creatures. Lots of room for development here and no two adventures will play alike (due to multiple adventure paths and foes).
B4 The Lost City (TSR): This old school original D&D module consists of a pyramid buried in the desert sands which holds various degenerate groups battling each other for control of the underground empire.
X1 Isle of Dread (TSR): Lost island sandbox setting with lots of different adventure ideas
WG4 Lost Temple of Tharizdun (TSR): written by the master himself, EGG, this AD&D adventure takes place in a long abandoned temple to a dark god hidden in a mountain valley. Initial conflict is against monsters who now inhabit the structure, but if the party delves deep enough they will run into Things Best Left Undisturbed.....!
Axe of the Dwarvish Lords (TSR): This AD&D supermodule written in the 90s takes place in an long abandoned Dwarvish citadel now inhabited by an army of goblins.
Gates of Firestorm Peak (TSR): This 90s AD&D module takes place in a weird, otherworldly mountain that has connections to a "Far Realm" of madness and insanity. Sounds like it would fit right in with Raggi's stuff!
Not as easy to acquire are the classic Judges Guild modules Caverns of Thracia and Dark Tower (however, the 3.5 reprints should be a lot easier to find and are backwards compatible). Both are great and concern ancient, underground empires with lots of evil things lurking about.
ISTR d20 Rokugan has a scale bar on the map.
The following image looks to be the same
From: http://brennor.dyndns.org/~steve/L5R/CombatMaps/map_rokugan.jpg
Best Answer
Those are "breaks" indicating that the cave keeps on going generally in the same way for X feet (' being the abbreviation for "feet"). Drawing that all out would make for scale problems on the interesting parts of the map, so long runs of identical cave are elided and those notations added.
Real world e.g. cave maps have similar devices, though not always looking exactly like this.