An unofficial walkthrough for MYSTERY HOUSE (a text-and-graphics adventure game made in 1980 by On-Line Systems / Sierra On-Line). Full documentation for gameplay written in Markdown with comprehensive dialogue, input commands and responses, alternate endings, and a list of all possible inventory items.

Accompanying style guide for the 1980 HI-RES ADVENTURE game MYSTERY HOUSE walkthrough with all formatting, spelling, grammar, and punctuation usages and code excerpts documented in Markdown.