I had a few minutes to look through some old files on one of my computers yesterday and found the old Swords & Wizardry Quick Start by Michael Shorten. As I was rereading it, a passage in the Players section stuck out to me:
When you play, you describe what you're doing and the Game Referee tells you what happens. In almost all cases, the Game Referee gives you one of two answers: "Yes" or "I think you have a chance of doing that - roll dice and tell me what you get."
That got me thinking about all of the games I've played where the characters' actions were too quickly limited by the DM saying “no.” I've experienced it both playing and running games. And I don't really want to do it anymore. I want all of my games to default toward permission rather than exclusion of player action.
That doesn't mean that the characters' actions shouldn't have consequences, but I want characters to have the chance to try anything and do crazy things without any kind of automatic restriction.