When comparing Open d6 vs Warrior, Rogue, & Mage, the Slant community recommends Warrior, Rogue, & Mage for most people. In the question“What are the best tabletop RPGs?” Warrior, Rogue, & Mage is ranked 11th while Open d6 is ranked 22nd.
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 Light ruleset
Pro Easily expanded and adapted
Pro Beginner-friendly
Pro WR&M derivatives can be shared and even sold freely
Released under the Creative Commons Attribution 3.0 Unported license, which means you can create WR&M derivatives and share them freely or even sell them. It’s the same open license Fate Core uses.
Pro Good if you like Simulationist RPGs
If you like RPGs putout by the big publishers, you will probably like this game.
Cons
Con Complicated magic system
Con Simulationist
GM-based
Unequal distribution of authority
If you like Story Games (i.e. GMless, Collaborative RPGs) this is not for you.