RyanD said:
We know that certain GMs consistently run games that are "more fun" than average. Studying those GMs and trying to reduce what they do to a reproducible system that could be used by others is a potentially fruitful line of research.
I'd focus on style compatibility, the GM's ability to adapt to unexpected events, and the social skills of the participants.
RyanD said:
Learning how to identify what kind of person each player in a group is, and ensuring that elements of each game session appeal to each player's needs is likely to make the game "more fun" overall.
There are two schools of thought on this subject. The first is to create games that cater to a particular style at the expense of the others and filter the group so they all share a common style or styles. The second (which I think you chose for 3e and Robin Laws tackles in
Robin's Laws) is to try to help GMs create games that can keep players with different styles happy.
RyanD said:
What I do not think is helpful is sustaining the conventional wisdom that says "rules lite games are more fun to play". This statement arises from a chain of logical reasoning: Rules make games complex. The more complex a game is, the harder it will be to play. Therefore, reducing the number of rules should make a game easier to play. The easier a game is to play, the more fun the game becomes. Thus, rules lite games are more fun.
I think there are some other factors in play. I think there is a style issue, a control issue, and a "training wheels" issue at play here.
First, rule-light play fits some styles of play better than others. This hobby has two gatekeeper systems -- D&D and, to a lesser degree, White Wolf games. To a certain degree, this gatekeeper effect naturally excludes certain styles that are poor fits for those systems (or the groups that most commonly play them) but some people who are poor fits for D&D stick with the hobby because they see the potential in it. Those people are never really happy with D&D and they want something different and (perhaps correctly) feel that the hobby could attract more people if there were a rule-light entry vector. So a lot of the people trying to make a better mouse trap are the people who don't like D&D because the people who do like D&D don't need a better mousetrap. But since everyone seems to have trouble understanding other play styles, they think their alternative should be better for everyone, when it really isn't.
Second, I think are a certain number of players and GMs (often those who think of RPGs more as stories) who know how things should be resolved and even know how things should turn out. For these people, the rules and dice fight them because, at best, they will confirm what they already think should happen and, at worst, will tell them something they think is wrong. For these people, a rule-light or diceless system feels like liberation because they no longer have to fight a system or dice that gives them the wrong results. Things like hero points and fudge points are another manifestation of this preference.
Third, the rules often teach people how a game should work but once people know how a game should work intuitively, they don't really need the rules anymore. They get in the way the same way training wheels start to get in the way once you learn how to ride a bicycle and won't fall anymore. Further, they spend so much time dealing with how much the training wheels bothered them once they learned how to ride that they forget that they needed them at first and that other beginners might need them, too. So rather than advocating systems that are appropriate for beginners, they suggest beginners start with games that really work better for people who know what they are doing. It's like a person who learns how to ride a bicycle feeling just fine after taking the training wheels off and then suggesting that all beginners start without training wheels.