Fallout Retrospective Interview

No Mutants Allowed gathered the leads of the Fallout series during its 8 years under Interplay and asked them several questions in a "retrospective interview." It's a good read with some interesting answers in there.
Give us an idea of the creative process involved in converting the game from pen and paper to a computer game.

Leonard Boyarsky

That was easy for me. I let other people do it.

Chris Taylor
The paper and pencil gaming was something we tried to emulate. I'd use the GURPS library as a reference. We were working on the Brahmin (two-headed cows) and Tim was wondering about rules for two-headed creatures. I referenced the GURPS Bestiary for the two-headed rules there to give us an idea on how to implement anything special for them. Mostly, I treated the design process as if I were going to be running a paper and pencil game for the rest of the team. I laid down the maps and keyed them to encounters that I then typed up. The second pass added the dialogue trees to the design docs and that was very computer-y and not so paper and pencil-y.

Feargus Urquhart
There are a lot of different things that you need to take into account and a book could probably be written on it, but there are probably two big considerations. The first is deciding how faithfully you want to follow the rules when it comes to the flow of combat and dice roll resolution - this is a part of the turn based vs. real-time combat decision. If you want to exactly represent GURPs, D&D or most other PnP RPGs then you have to go turn based, which was the decision for Fallout when it was GURPs. For Baldur's Gate, the decision was to goto real-time, but to still have a character follow its own round. The second is what you want to do with all the other aspects of the RPG system, which usually mean the non-combat skills, attributes and abilities. It's out of these that come the use of skills and attributes in parts of the game like Dialog (Charisma, IQ, Speech, etc..). I think it's really important to focus on both those elements of an RPG system or you'll miss the flavor of the system and how it is tied into the world of the game.
And here's an interesting remark for those following Obsidian's Alien RPG.
How did Fallout's development and design influence your later games?

Feargus Urquhart

To this day, I still think about how we addressed problems in Fallout and use them as examples of how to do things. Josh Sawyer was just talking about how the story and quest structure of Fallout worked and how we should apply that to the Aliens RPG that we are making. What is also a great influence on me is the desire to do what we did in Fallout again, we really were able to make a world that fit with the game and the RPG system. It just all worked well together and answers to problems often just represented themselves.

J.E. Sawyer
Playing and working on Fallout made me appreciate how one should develop and promote player choice in games. It's hard to explain succinctly, but the best way to support non-linear gaming with meaningful gameplay choices is to "let go" in a lot of ways. I think game developers tend to want to tell a specific story to players, and that very often conflicts with a desire for open exploration or other forms of player freedom. If you break down Fallout and Fallout 2, there are essentially three or four plot-critical elements in the whole game. Everything else can technically be skipped. But the method of Fallout's presentation allows the story to be revealed in a logical progression without binding the player's hands.