When comparing Open d6 vs Old School Reference and Indexing Compilation (OSRIC) , the Slant community recommends Open d6 for most people. In the question“What are the best tabletop RPGs?” Open d6 is ranked 22nd while Old School Reference and Indexing Compilation (OSRIC) is ranked 32nd. The most important reason people chose Open d6 is:
Open d6 includes rulebooks for Fantasy, Adventure and Space settings.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Includes rulebooks covering the more common genres
Open d6 includes rulebooks for Fantasy, Adventure and Space settings.
Pro No special dice required
The game can be played with common six-sided dice.
Pro A simplified variant, called Mini Six, is available
Mini Six is a fan-made variant of Open d6 that aims to be a distilled version of the Open d6 system.
Pro There are theme-related books available to start various types of games
D6 Space is West End Games old "Star Wars D6" game with all of the licensed Star Wars names removed. It's a stand alone complete game.
D6 Fantasy is a standalone ruleset for running a D&D type game with the D6 system.
D6 Adventure is a standalone ruleset for using the D6 system in a Wild West, spies, or modern adventure game.
All three have supplement books (Spaceship design, magic, aliens, etc).
Pro Each rulebook has a good introductory section
Pro AD&D 1E aligned to d20 SRD
OSRIC is based on the well-known 1st edition of Advanced Dungeons & Dragons, arguably the most popular RPG of all time. It doesn't stick to is slavishly, though, but instead brings in a few innovations from the later "d20 SRD" to regularize the system a bit and fill in some of the gaps. It is, however, still very much a 1980s system.
Cons
Con Complicated magic system
Con Complex and inconsistent rules
There is no "general system" for doing things in the game - everything is a special case. This can result in a lot of page-flipping to find the particular rules for something, and in problems for new GMs who don't yet know the system well, or who aren't comfortable with improvising.