If the premise of the Great Tower of Oldechi had one problem, it was that every floor was separate from each other. The players might meet other characters who climbed the tower, but an NPC from Floor 1 would not show up on Floor 2, Floor 3, or ever again. On the one hand it let me focus on the important recurring NPCs, like other climbers and the tower-spanning organization, but on the other it quietly encouraged the players to do anything they wanted to anyone they wanted. If they burned down a town for giggles, that’s fine! Nobody in later floors would know.
This became most clear in Diana’s floors because they were divorced not only from each other but from D&D. Alex’s floors felt like a campaign or video game where you killed the boss and moved to the next area, but vanilla D&D is kind of like that anyway. Diana didn’t even have that structure because she told the players “this is a puzzle, and when you solve it you advance”. Her area of the tower was even less real than Alex’s and it showed even fewer long-term consequences because it lacked even the same threat of combat death.
The players pointed this out to me somewhere in Act 2 and early Act 3, and once I looked at it I realized they were right. So for the sixth section of the tower I wanted floors that connected to each other even if it wasn’t obvious at first. And I needed a tower guardian who made sense for this concept and represented an escalation from Diana as we approached the end of the campaign.
Sennacherib was probably the longest-reigning tower guardian. He’d been around to see what hundreds if not thousands of parties had done with and to the tower and the NPCs that lived in it. By the time the party made it to him he had long ago become sick of the nonchalance with which climbers fought, threatened, insulted, demeaned, and murdered people when they thought there would be no repercussions. So he inflicted consequence on the players.
All of Senna’s floors were set in the same area at different points in time, a fact that players didn’t learn until they had already beaten the first floor. His section of the tower was a branching timeline where a party’s actions in Floor 23 would create a Floor 24 showing the world some hundreds of years later. If the party set themselves up as heroes, they might still be revered in the future and asked to save the town from demons. But if they murdered everybody they saw, they would be history’s greatest villains and hunted as soon as they arrived in the bleak ruins of the future.
To my players’ credit they did not kill everyone. But they did try to kill the entire ruling family, so let’s not give them too much credit.
But that’s where the puzzle got interesting. The players could very well have opted to burn down the entire city in Floor 23, which would have triggered a level-up because it sufficiently affected the future. If they had, Floor 24 would have been a barren wasteland with no buildings, creatures, or activity of any sort. I trusted the party not to do this because they’re good players, but the possibility existed (not the first time I put an instant-win or instant-lose opportunity into the campaign that I trusted the party to either not recognize or consciously reject). Because of the way the floors branched it was unlikely that another party would ever make it to the same version of Floor 24, so anybody who made it there would either starve to death, die of old age, or spent eternity trapped in a prison they accidentally built. Diana had cute little puzzle floors with rules and an outcome, like Professor Layton. Senna was more like a Sierra game, where a choice in the first room could lead to guaranteed death at the very end and there was no way to know until you got there.
The floors themselves were a D&D-based, pseudo-, I’ve-never-actually-been-so-please-don’t-hit-me version of Tokyo. Floor 23 was the city in the feudal era, Floor 24 was modern, and Floor 25 was an unspecified time in the future. Finally I got to use all those ninja minis, but more than that we broke with the D&D tech level and introduced guns and cars, then laser guns and flying cars. At one point the players fought a pitched battle against (and eventually with, because my players are like that) a platoon of tanks in an intersection in the middle of the day. It’s the sort of combat you just don’t expect to have when you’re used to a campaign where you play goatball.
Because of this Senna set himself up in a weird way to the players. He was happy to give them ways to show off, like Jay, but he also was happy to test their mental mettle, like Diana. What made him different is that he made everything into a consequence. Jay and Diana didn’t care what the players did as long as it fit some specific idea of success. Senna’s vision of success was a lot more fluid and murky, and it’s more accurate to say he had a lot of visions of failure and a few gaps in between*. This gave him a different relationship with the players and the campaign. With the other guardians, the players either liked or didn’t like them. Approval wasn’t a factor with Senna. I think he was the first guardian that actually scared them, and that speaks volumes about his DMing style.
In terms of style Senna was somewhere between a simulationist and a narrativist. He felt that the world should progress without the players and that anything they do should have consequences like it would in a non-tower environment. But his world wasn’t the star of his story, it was the hero, and the villains were the PCs. He wanted them to look at themselves, think about what they’d done and what they intended to do, and change for the better. His floors had the first real party conflict, with players drawing swords against each other and eventually going through redemption arcs. He forced them to react rather than act, putting them on their back foot for the better part of his section, and he gave them (relatively) long-term villains who went through character growth that led to their own destruction.
Which was sort of what his section of the tower was about. The capstone for Senna’s section was Floor 26, a literal junkyard no matter what the players had done previously. At his core Senna felt that players by their nature cause ruin and decay. It doesn’t matter if they think they’re heroes or world-savers because they function by death, destruction, trickery, theft, and every other action that deserved to be punished. And he made advancement from Floor 26 the ultimate representation of that goal: the only way to advance was PvP. If a party wasn’t willing to turn on each other or kill another party they couldn’t advance, and if they were willing they faced Senna and his hanging tree in combat. Because regardless of what the PC’s intentions were, they had killed a real person with hopes and dreams, perhaps even a friend of theirs, and that merited a judge and an executioner.
The players rightly viewed this as the ultimate kick-the-dog moment, and they didn’t take kindly to being forced to kill another climber and then being punished for it. In the same way that players don’t appreciate being forced into a corner and punished for getting out of it, the party didn’t appreciate that the only solution to Floor 26 was the only thing they had managed to avoid for the entire campaign, and in fact the things that differentiated them from many of the campaign villains. But more than just giving the party somebody to punch, Senna gave them a transition to the final section of the tower, where the players and the characters got their chance to prove whether or not they were good at heart. But that’s another post.
* — I’m willing to bet that a plurality of my players will say this is closest to my style, and that of course I would put myself into the campaign as the grumpy old man who’s resigned himself to disappointment. I’m more inclined to think that I have elements of all seven guardians, or more accurately they all have elements of me.

In Defense of the Indefensible
World Engineer has a post about the impending 5th Edition, and I find it hard to disagree with most of what he says. Fighting over editions is bad, there’s no need to convert people, and so on and so forth. But while I agree with what he says, I think I disagree partially with why he says it. I don’t think that people complaining or worrying about 5E are motivated by childishness or spite. I think they’re motivated by fear.
I’ve been going to my friendly local gaming store for longer than I’ve been a friendly local gamer. Now I can’t swing a cat without hitting two ongoing campaigns, but for a while there were only two or three people willing and able to run a regular session. If you wanted to be in a campaign, you had to go through all the normal steps (seeing if a spot was available, making sure you were free on the day in question, arranging transportation, tolerating the other players and house rules) but with the added complication of a limited option pool. If you didn’t like either of the current games, you had no game.
The standard blackjack-and-hookers options didn’t apply either, because the players were similarly limited. There simply weren’t enough people to guarantee a group willing to play in 2nd Edition or try an indie system. Most of the available players were college students, which meant they were playing largely what they knew from high school and what the local clubs supported, and at the time the hotness was D&D 3.0. Even if I wanted to start a GURPS session gathering a group was an uphill climb. Campaigns with only two players aren’t very fun (trust me—I didn’t learn my lesson the first time).
When an edition change occurred, the problem escalated. When 3.5 came out, some 3.0 campaigns stuck around as a show of defiance but gradually petered out. When 4.0 came out, we had the same issue. Anybody who wanted to play in a 3.5E campaign was out of luck unless they managed to get into the one campaign that was playing it.
I suspect a lot of this mindset is still around. Folks in smaller areas or with limited gaming options worry not about the existence of a new system itself but the presumption that it will be adopted locally. It’s a Hobson’s Choice: if I don’t like 5E but every gamer in town moves to it, I can either play in a system I don’t like or not play at all. In that sense, a new edition may actually diminish my enjoyment of the game.
In an online world or with a large enough player pool, the problem is instead merely a dilemma. I can either stick with the people I like and play a game I don’t, or leave the people I like and look for a system I do. There’s something to be said about knowing that my friends are enjoying themselves elsewhere while I’m taking whatever I can get.
This is related to but distinct from the very real expectation that a new edition will prevent a company from expanding the old edition. When 4E was announced, 3E and the OGL went away (until Pathfinder, but it’s not like we knew that would happen at the time). When 5E was announced, 4E stopped as well. The edition died in the same sense as a language. It could not expand except via house rules, and coupled with players moving to the new edition the interest in expanding it faltered in kind.
We’re people. We have a strong loyalty to our favorite things, and anything that is not that thing is in some way less (or else it would be our favorite, of course). A favorite edition is no different. Every person who adopts 5E is a person who isn’t looking for 4E and thus isn’t interested in what I want or have, and the issue is exacerbated when adjacent editions are so different. Players aren’t really attacking people who play other editions because they think those players deserved to be attacked. They’re lashing out as a survival instinct: “if you would do the thing I do and enjoy it as much as I do, the thing I like would not be dying”.
They’re wrong, of course. No system or edition can last forever. Eventually 5E will die, and if it was sufficiently profitable 6E will come out, and we’ll complain about that too because it shows too starkly how dead 5E is. Pathfinder will die too, and in the sense of system expansion it may already be dead so Paizo can focus on world-building and adventure modules. Any gaming historian can rattle off a dozen systems that don’t have the player base they once did. The only systems that stand a chance aren’t really systems as all but vague concepts. Apocalypse World and its related games are large and varied, but that’s mostly because its core concept fits on a sheet of paper and trusts DMs and others to build the system for them. It’s a like a building—a house of bricks may fall, but bricks will still live in another building somewhere.
So while I can see why some players are worried about 5E and what it means for the system they want to play, I’m not. I tend to take a system and pervert it until it’s something I enjoy anyway, so doing it all over again with a new edition strikes me as more of an intellectual exercise than a death knell. But I do think I understand why people are upset, and understanding it helps me. If I know what players liked about a given game, I can adjust my game to work with it, like applying story game principles to D&D. It’s a little more fire, a little less brimstone.
This all assumes that people aren’t complaining about how 5E is a money grab. Of course it is. A business’ job is to find ways to get more money out of their customer base. By this definition your shoes are a money grab. “5E is Wizard trying to get more cash out of us” is no more a valid complaint than “cars travel on roads”. Don’t worry about whether a given game costs money—worry about whether it’s worth that money to you.