Interestingly enough, a recent piece by Eskil Steenberg (creator of Love) compares players who blindly follow scripted events to creationists. "If something happens they think it is because of a decision taken by a designer rather than as an effect of the logic of the universe," Steenberg writes. It's up to us, as active players, to take back the power to impact game worlds in unusual ways. We have to struggle out of the straightjacket that we would be placed inside by certain designers. Let's be the Devil we know we can be.
This is a two-way deal. Some designers are on board with providing as much player freedom as possible (and despite my examples above, Mount & Blade is definitely in this category.) It's the reason why Deus Ex still holds up as a must-play game. The reverence for that title isn't really down to the plot (unless you're an avid Coast to Coast fan,) and it certainly isn't anything to do with the voice acting. It's the respect given to player agency that is present in almost every section of the game.
Some make the mistake of thinking the genius of Deus Ex rests with the choice of taking three distinct paths: stealth, violence or wits. Were it so simple (and restrictive), the game would not be remembered so fondly. Sure, you can max out one of those routes, but it's also possible to create a JC Denton with super-speed legs who's also a heavy weapons and hacking expert. When you're leaping around, popping off rockets, aided by some hacked bots, it's not really a "path" you can fit into a neat little box. And that's the point. The skills and environments allow a persistent player to do ludicrous, bizarre things - like reducing yourself to just a head and rolling on-board Jock's escape helicopter. Visionary actions like this can only be achieved if you listen to the little voice in your brain.
Seven Deadly Sims
Of course, it's no coincidence that some of this rebellious devilry tends to take the form of morally questionable acts. The Devil is player agency, and if he is restricted he will encourage our darker sides. Don't believe me? Then let's take a quick straw poll: How many of you passed the time during Half-Life 2's locked-room exposition scenes by smacking Eli, Alyx or random pieces of scenery/NPCs about the face with a crowbar, shooting mugs around the room or just bouncing up and down on top of a nearby surface like a gibbon? Exactly. You felt trapped, didn't you? You just fancied finding out whether you could murder some plot-critical characters, or at least get them to react to some strange behavior. It's OK. I understand.