1. Yes, 4e. We began our campaign years ago when it was the only option, and translating to 5e didn't seem feasible. Also, I was involved in the early playtests of 5e and did not like it. Since, I have yet to have anyone explain to me what's so great about 5e. I know during playtesting they made a huge deal about how "Skills" in 4e were absolutely awful and 5e was going to totally revamp it with The Plan. And I pointed out what was wrong with 4e Skills, and pointed out that The Plan did literally nothing to address any of that, and people told me but no, it'll be better. Just see. Then real 5e came out and it handles skills exactly like 4e did, with very slightly fewer, and slightly different names for some of them. I am open to someone explaining why 5e is an improvement, but I have asked a lot of veteran gamers and have yet to get a real answer. 2. Yeah, this isn't a standard "dungeon crawler" either. I don't think I formalized it to your Pillars, but I do something very similar. We can only meet for about two hours at a time, so one combat encounter per night is about all we can handle. Our system is as follows: We pick a date to play. I email everyone with a little story blurb, either beginning or continuing the story, letting them know the set-up for the whole quest or the fall-out from their most recent encounter. At this point I typically have a general sense of what I want the next combat encounter to be. Then we have a few days of back-and-forth emails where the players will roleplay a bit, maybe make some decisions about how they want to proceed. Typically their decisions simply flavor what happens next, but every so often they throw me a curveball and decide to go way off-script and I have to shelve the idea in my head and come up with something unique. Then we typically find some way to do an email skill challenge; the big change in my system is I make everything a group check. Everyone rolls what they think is appropriate, what they think they can contribute to overcome this next challenge, and I total up everyone's score, sometimes apply a few bonuses for creativity or teamwork, and they all pass or fail together. By then it's usually time for combat. I do typically try to throw in at least one or two interesting terrain features though I've been slacking on that somewhat recently. The combat usually has at least the flavor of something narratively thematic (though I know the Lore of D&D far better than my players so mostly it goes over their heads). Whenever possible, I like the combat encounters to speak someone to at least one player's backstory or sub-plot. Beyond that I try to build up my crunch a lot, then cover it with fluff. Like, I've found my players aren't fans of Lurkers so I save those for when I want to be vexing. One encounter they'll face paper tigers, the next one glass cannons behind bullet meat. Minions don't work out, mechanically, and Solos tend to end too quickly, so I mostly stick with Standards and Elites. It's not as flagrantly interesting as your Pillars, but my players do tend to think tactically, and it keeps them on their toes. They really seem to enjoy the opening gambit of any encounter as they try to determine which bad guys are squishy, which are gonna deal damage, and omigod is one of them going to dominate someone. 3. So, yeah, like you, I like to have mystery, and roleplay. We just tend to do most of that via email, though every so often something is relevant enough that we take the time to meet and do it in person. Heh, I recently had someone set them up to make it look like they hired assassins to kill the Emperor. I apparently did an excellent job, because at one point one of the players, OOC, turned to the guy next to her and asked, "Wait, we didn't actually do this, did we?"