I don't think any of my players would think my NPCs were passive - they're always plotting!
One reason I try for a very clear direct GMing style is that there's so much going on that otherwise it would be indecipherable to the average player, and would just seem like a big confusing mess.
Yeah, that's not quite what I meant. It's more that, to me (and I'm not sure this is really a rational thing), having the NPCs/monsters actions create "passive use" DCs for the players to roll against makes them feel passive in a wider sense. Partly it's the simple fact that, if the players roll for every contest, the players will always know that there
was a contest to be rolled for. Partly it's the non-rational psychology of me, as DM, feeling like the NPCs are running around just erecting cardboard cut-out barriers for the PCs to knock down, instead of having an active agenda of their own. Personal preferences based on personal reactions, basically - I've no idea how rare or widespread it may be.
I use Passive Perception a fair bit, but only to reduce swinginess - so no problem asking "What's your Passive Per?" - usually if it's too low the reason swiftly becomes clear as there's an immediate ambush.
NPCs hiding works this way, for sure; also "environmental effects" like the old "dwarves realise when they encounter sloping passages 1/3 of the time" or "elves detect secret doors 1/3 of the time just by passing near them" stuff.
Something I also do is give players active rolls if they are about to trigger a trap. This is basically to stop the pixel-bitching stuff with endless checking and searching; they get a simple, automatic chance - succeed and the action stops just before they set the trap off, fail and the action stops just
after they set the trap off...
I assume they don't - vast numbers of Heroic Tier NPCs get chomped on by the Epic Tier monsters IMCs - offstage.
So the "magic zoning" applies only to the PCs? That's even
more anti-simulationist, isn't it?!
Actually, with 4E I generally take the view that the PCs are the only "characters, as such, in the world. All the NPCs only "exist" as "monster statblocks" and obey the "monster rules" in terms of the numbers being mutable to suit the party level (so, a 1st level NPC meeting a 12th level party will morph to a 9th level minion). So the "hordes of low level NPCs" don't exist, per se - the world isn't simulated to that degree.
And there's nothing to stop my level 7 Wilderlands PCs seeking out the EL 16+ Dead Queen's Valley, or the Cryptic Citadel of the Invincible Overlord, or whatever. But I do take it that (a) Epic Tier threats are fairly rare on a global scale, they typically have to be sought out and (b) the PCs have at least a chance to locate adventures of suitable level, with a bit of scouting & smarts.
The question is, though, why are these Paragon or Epic creatures confined to those Valleys and Citadels? If the Invincible Overlord has scads of Paragon level creatures to command, why doesn't s/he just send them out to take over all the low level lairs and towns? Why hole up in some dingy "Paragon dungeon" when you could take a kingdom and live in luxury?
Yes, it's clearly a matter of preference - I like to stretch myself as player & GM, and in-character roleplay is one of the main things I play for. If you can't make a good-faith effort at playing a charming swashbuckler in-character, ripping off cheesy lines from movies or whatever it takes, but making an effort - then I don't want you playing a charming swashbuckler at my table. I often play with strangers, and even if playing with friends I don't want them playing in a way that I won't enjoy. But I'm not saying my way is better, just better for me.
That's a fascinating example of what sounds like a Simulationist agenda (exploring "what it's like to be a...") specific to the player/actor's experience. Interesting and perfectly valid (obviously), but not a drive I think I have ever felt.
Both your examples comply with my GMing approach too - people tend to do things for understandable human emotions like greed, ambition & revenge.
Even when they are not human?
Actually, I very much agree with "understandable" motivations for non-player creatures. It's akin to the "computer player" playing by the game rules (i.e. not "cheating"). The reson is simply that, if the rules as understood by the players don't apply to the opposition, how the heck are the players supposed to figure out what they can and cannot/will and will not do? If the opposition are not, at some level, comprehensible, the whole thing becomes an arbitrary crapshoot.