Morrus said:
That's an interesting view; clearly WotC believes otherwise. Where do you derive the conclusion that the OGL is what made D&D the big dog - as opposed to, say, ownership of the established brand name combined with far greater resouces?
The brand name is what makes D&D a 'big dog', but I (and many with me) think that the OGL made D&D a 'bigger dog'. Why would I think that?
1.) The OGL created a LOT of goodwill from the gaming community, and beyond. It was some very good free publicity for D&D. Comparing it with Open Source Software made D&D more 'normal' and 'acceptable' to the general populace.
2.) The OGL (and D20) was linked to D&D, that made it a popular choice to make RPG material for. Because D&D sells, so did OGL/D20. Third party publishers made supplements that WotC would never make or only made much later, that attracted folks that would never have looked at D&D without third party products. Necromancer promoted a 1E feel for 3E D&D, that attracted a lot of older gamers to 3E. The list is long, folks that would never have touched D&D were suddenly interested in rolling that D20. Even if you were playing Spycraft, Traveller D20, Babylon 5, Conan, or a Mecha game, you were using the basic rules of D&D. That made D&D the defacto RPG operating system.
3.) Having a larger piece of the RPG market pie tied to your system not only hurts your competition, but at such a small scale, drives your competition out of business. Small print runs are not viable for most publishers. Since the introduction of the OGL, I've seen a lot less non-OGL game systems in print from the distributors. The digital age (pdf) and print on demand have created the possibility of small scale distribution, but those solutions just don't have shelve space at the RPG shops.
WotC eliminated much of the competition in the last decade or at least tied the competition to the D&D system. After that decade most of the surviving publishers that are tied to D&D are so dependant on D&D for their income that WotC can dictate more profitable (for WotC) license terms for a new version of D&D. Tying those publishers even closer to the D&D system, with even more control for WotC. It's a very cunning move on the part of WotC.
I'm very curious what companies like Mongoose will do, they were created on D&D accessory sales and attempts at expansion have faltered or failed (miniature lines have collapsed). On the other hand, companies like Fantasy Flight have moved on from publishing D20 material as their main source of income (fifth largest board-game company in the world). Green Ronin (Mutants & Masterminds, True20) and Crafty Games (SpyCraft) have developed their own unique systems based on the D&D system, but don't need a way to tie their systems into D&D 4E. I'm curious to see if Paizo will continue with their Pathfinder system under the OGL, and if they'll succeed to get a decent following/community.