Solo Dungeon Crawler - Solo DnD Tutorials

I recently came across an interesting situation in my solo original Dungeons & Dragons campaign. My adventuring party forced open a door in the underworld beneath the "Castle of the Quest" and subsequently found themselves in a corridor filled with smoke! It therefore seemed appropriate to have some sort of rules to hand regarding vision as surely this vision would be obscured by the smoke and hinder the characters in some way. Obscured Vision in OD&D In order to discover which rules might apply (or point me in the right direction in terms of handling the situation) I decided to review all the original D&D rulebooks. In Men & Magic under the spell description for Insect Plague it tells us that this spell "obscures vision" indicating that some such mechanics should apply in the game. In Greyhawk the description of the Horn of Bubbles says it "completely" obscures the holders vision for 4–12 turns. This implies the obscurity has a spectrum fr