Here’s a nice random dungeon map generator. They have a very old school look.
fantasy
Song of Blades and Heroes Solo Rules
Here are some interesting thoughts on playing Song of Blade and Heroes solo.
Solo Lord of the Rings Battle Game Rules
Isuldur’s Bane is the name of a free set of rules for playing Games Workshop’s Lord of the Rings Battle Game.
Three Plains 15mm Fantasy Wargaming
Three Plains is a free fantasy wargaming system. It also comes with free print-and-play figures.
Brutality Skirmish Wargame
Brutality is a miniatures agnostic skirmish wargame set in a science fantasy realm. You can get a free version at the link.