Background - My Group's Gaming Style
When I GM, I run games loosely from a rules standpoint, and do not feel bound to adhere to what the rulebook says when it doesn't make sense in a given situation. I adapt things to fit the game-world reality over the written rule and use my judgment as the final authority for in-game events.
This is how all the groups I've been in "back in the day" played. The OSR guys have codified this approach more recently as "rulings, not rules" - back when I was playing in the 1e/2e days that was just the way things were, and people who insisted on the "rules as written" were stigmatized as "rules lawyers". Nowadays, this is more common and "the rulebook is the final authority" is accepted behavior in many gaming groups. That's fine for them, but is explicitly not for me and my group. If our style is not for you, move on to another question please; I'm not interested in whether you think this approach is right or not. It works for the groups I play in. I am interested, however, in how to help new players who aren't used to this mode of play become comfortable with it.
We have an existing large gaming group playing a variety of existing game systems. We've run long campaigns in Pathfinder, Savage Worlds, Alternity, Mutants & Masterminds, GURPS, Silhouette, nWoD, and shorter games in Dresden Files, Feng Shui, Unknown Armies, Godlike, Adventure!, and many more. At the table, players own rulebooks and roll their own dice. I am not looking to retool the group or choose a new system or make major changes to our order of operations. Things are working well for us and we are having fulfilling gaming experiences.
This is not a discussion about D&D or any game in particular, it's about a type of mindset brought to any game. We rotate game systems and are not a "D&D group." I have seen people used to a Rules Are God approach apply it to Savage Worlds, for example. Let me use an example from one of our Savage Worlds campaigns. One player had a big brute of a character, and we were in some building with ninjas or something attacking us from the rafters. The brute couldn't hit them, so he wanted to bash the rafters, knocking them off balance - a Strength Trick. And it made sense in the situation. However, the rulebook only allows for Agility and Smarts Tricks, so the GM objected to the action on those grounds. This example shows that regardless of how big or small the ruleset is, it can be approached as "guidelines" or "the law".
This mindset, or its opposite, can be maintained across game systems - again, it was largely the default metaphor back when all there was were 'trad games.' I understand some people may not believe that, but for purposes of this question, you have to take it as a given that we are able to successfully play all kinds of games without valuing the rulebook over the GM/game world reality.
The Question - Player Onboarding
We get new players from time to time, and sometimes their previous gaming experience is so steeped in 3e/4e D&D or similar games to the point where they just instinctively go to the rules over rulings. They want to spend ten minutes looking something up rather than just running with it, or are surprised when I say something can't happen, or look at another player who tried something not defined in the rules and succeeded like they're cheating or something. They want to build whatever options they can buy the book for into their character and are sad when I restrict them. I want to help these fragile souls adapt to our gaming style.
Assuming we don't think that they are just so incompatible with our playstyle that we wouldn't invite them in the first place, how do we help a willing new player become comfortable with our more freewheeling approach to the game? Naturally we inform new players of our approach, but group and individual approaches are poorly defined things, it's not as easy as matching our label to their label and voila, they slot in to our style perfectly. When anyone joins any group, there is a certain amount of adaptation that happens implicitly and explicitly. We want to facilitate the culture change process a new player may be going through.
To state it another way, if you are more comfortable with Threefold Model terminology, I am looking to onboard willing new players coming from a past gamist-heavy experience to a game based more on a simulationist mindset (with a side dish of Rule 0 and immersion). Even willing players can have a hard time overcoming their baggage from previous gaming experiences, as our experiences form some of our default expectations in ways so subtle we are not always cognizant of them. What are techniques we/they can use to help shift gears?
I'd rather not change our play dynamic wholesale, like "take the books away from everyone."
Please read this question carefully before responding. "Don't do that," "Don't get players that aren't exactly like that," "Change your rule system, you have to play indie games," "GM fiat is evil," "You can't play a game like D&D that way," "The threefold model is a scam," "My GM touched me in a bad way once," etc. are not answers to my question. The question is: I have a group that plays a variety of games and generally doesn't value strict rule adherence. Assuming someone wants to uptake this different playstyle, what can we do to help them do that?