NewsThe Glatisant, curated OSR mailing list.
2-Minute Tabletop, a website featuring maps, how-to articles, and ready-made encounters for many different environments and monsters.
Worldographer, a map-making application for old-school hex maps.
Dungeon Scrawl, a dungeon map drawing program.
Adventure and Idea Generators
Donjon, random table generators for every occasion.
WTF is my Quest? A random idea seed generator using the WTF? engine.
Who the Fuck is my DnD Character? A WTF? engine tool for creating character concepts.
Trilemma Adventures weird and wonderful one-page adventures (system neutral.)
Character Art Generators
Hero Machine, a 2-D comic-book style character art generator.
Hero Forge, a business that lets you design and produce custom RPG minis (great for taking screenhots for 3-D character art, too)
This Person Does Not Exist, randomly generated photorealistic images of human beings fit for Photoshopping.
Worldspinner Heraldry Artist, a tool for creating coats of arms for medieval fantasy characters.
Makehuman, a 3D modelling program to create posable character models.
The One-Page Dungeon Contest, an annual contest for the best one page dungeons. All entries are creative commons, most are linked on the site to where they are freely available, and the annuals are very affordable.
Dragon Magazine Archive, a collection of issues of Dragon Magazine on archive.org.
Dungeon Magazine Archive, a collection of issues of Dungeon Magazine issues on archive.org.
How to Make Cool TTRPG Pamphlets, a pamphlet on making pamphlet-sized RPG material, including useful links to art resources and templates.
Purple Sorcerer generators, dice rollers, adventures, and virtual table-tops for Dungeon Crawl Classics RPG
Fiascoplaysets.com, a collection of free, community-made playsets for Fiasco.
Music and Sound Effects
Free Music Archive, a library of free music.
Orange Free Sounds, an archive of short .wav and .mp3 files free for use (may require attribution.)
Ambient Mixer, a multi-channel sound mixing tool great for creating immersive background soundscapes. You can download mixes for offline use for a fee.
GIMP, a free, GNU analogue to photoshop.
The Deathtrap Games Rules Cyclopedia, my blog project to create an easy reference of helpful rules for custom campaign design and game development.
Open Game Engines
Forged in the Dark, an open engine for playing a growing enterprise of shady characters.
Mark of the Odd, an Old-School open game engine focused on problem solving and player skill.
Powered by the Apocalypse, an open storygaming engine that supports a broad range of genres.