dmccoy1693
Adventurer
Isn't it much better for the 3pp to take the OGL and run? Make a complete game of it instead of just an expansion?
In this scenario ... no. As a small press designer, I don't have any interest in making a complete game. Here's why, I have a day job. I have a family and a kid. I don't have crazy amounts of time on my hands.
I recently release a 68-page monster book for Pathfinder this past GenCon. When did I start writing it: the previous GenCon. That's right, it took me a solid year to get a 68 page book out, and that is with one of my awesome editors helping me write some of the NPCs in it and the other editor running a team of volunteers to make sure that the book sang with perfection. I'm not about to create my own game without a darn good reason and (using our combined example) adding in guns and changing the way ranged attacks work is not a darn good reason. Its much, MUCH more reasonable, both from a time investment standpoint and the sales standpoint, to just come up with a PDF of how to change ranged attacks work, add in guns, and add a few subclass options.
What is a reasonable reason to use the rules and go solo: changing the entire feel of the game. Taking the fantasy rules and making a superheroes game or a scifi game out of it. Or getting a super huge license that can make sales on their own like say Conan or the Lord of the Rings. That would make me want to go solo and possibly use the OGL rules as a base. However, if I got the Nina Kimberly the Merciless license, I'd just make a supplement using the existing rules. The game isn't going to sell well enough to justify the time to re-layout the existing rules, make changes here and there to exactly capture the feel of the book, commission artwork in DROVES to cover the hundreds of pages required, and then start writing all brand new supplements to keep the game going.
But frankly, if I did a guns supplement, I wouldn't change how ranged attack works. I'd create new equipment, add in a few subclasses, write a short clarification on how guns worked with the existing rules without changing the rules themselves, make a few organizations and other setting pieces to help incorporate guns into the game and call it a day.