I haven’t posted here much, but as someone who’s design minded and hates games that prematurely blow their load on large scale ideas, this one’s gonna be a rant.
While I haven’t played around in the code much (as I’m not a programmer, as much as I know game design), anyone can see this in action if they just look at how things function mechanically for long enough. The first and most obvious thing, which most players will realize exists in some manner after a few games, is the reality bubble. Online games do have a reality bubble of sorts, as it’s just smarter to not have the servers processing things that aren’t in use, hell most games do for that matter- You can glitch Super Mario 64 to hell and back by abusing unloading. But very few have such a large base of variables potentially interacting with it. Starbound is a decent example of one, and you get stuff like rain clipping through the floors and walls of your house on the edge of the screen if you’re not careful about how you build due to rain being attached to what the player can see. Starbound and Cataclysm actually handle the way plants grow off screen very similarly.
When you leave and reenter an area, taking your reality bubble with you, not only does that trigger enemy behavior, so that someone could, completely by accident, trigger a group of zombies a screen away that get lured to someone’s base somehow and demolish it without them even knowing… But things that are calculated outside the reality bubble and have to catch up would have to do so for however many players are wandering around your world. Meaning you’d need to have someone program all that logic and make sure it runs efficiently and without strange, gamebreaking bugs, as well as ensure the game is balanced in such a way that players can’t constantly screw each other over in really esoteric ways. They’d also have to find and rework a lot of odds and ends, such as the clothing fit system, which as far as I’m aware is a tag on items and actually doesn’t do any kind of a check against the player. Which means you can have a tiny Chinese girl who wears the same clothing as a giant nine foot tall mutant lizard from freaking Asgard.
The first thing you’re going to come to grips with is just what kind of multiplayer you want to attempt, which is going to depend on what the programmers in question can do, as well as what they want to do, and most importantly even if not your primary concern, what players will actually really enjoy. This is why you actually do need programmers at the idea stage, so you don’t overdedicate to a scheme that isn’t practical or possible.
You will have to start considering game design, and one of the first things that would go out the window (in some cases for better, in others for worse) are many of the typical things in a roguelike. Permadeath can maybe go or stay, but save scrubbing by nature is going to go, which is frankly something that keeps a lot of us playing who like the adventure and complicated nature of these games but not the super punishing nature of failure. Secondly, online games also tend to put more pressure on players optimizing for a variety of reasons, as just by introducing other players, even in a cooperative setting, indirect competition will arise.
And player versus player competition in a roguelike… Well, I don’t think I need to explain that one. The game will probably end up with a softcore setting that most of the online players end up using just because of that alone. That or a dramatically accelerated progression curve. Or have the game be strictly player versus AI. And whether you decide screw the average player or not, balance is going to become more difficult, and many (probably for the better, to be honest) changes will have to be made to player skills, mutations, gear, etc to ensure the game’s meta doesn’t end up lopping off half the player’s total options.
There’s also a plethora of (delicate) design choices that need to be settled on that will directly impact how you implement things on the programming end, so this is in fact a two way situation. Again, you need the people working on the actual code hand in hand with the people designing the gameplay. There’s a reason why Treasure used to have their lead designer also always be a programmer. Chances are you’re going to end up settling on a more mass-multiplayer, real time implementation of the muliplayer simply because that’s what most people are going to want out of a multiplayer Cata. As a survival game people are going to want some level of persistence and a world that feels like it’s there even when they aren’t. You could do a small server/client setup, but you wouldn’t get the same amount of impact or player investment you would on something bigger.
Assuming you do go for larger servers with higher player counts, and work out all the issues with the actual implementation of mechanics you chose… Well, there’s a ton of ways to deal with long term stuff, modern MMOs even give a few good ideas. But it will make cata a fundimentally different game. The whole reading or long term crafting problem can be handled how “logout” bonuses work, or long term away missions in a game like STO, I. E. you’d set your character to perform a certain activity while you’re logged out and for the next 24 hours they’d perform some combination of that activity and sleeping while you’re offline, in a sort of quasi space, with a chance to get a few injuries and degrees of success. But this would mean no more, for instance, preparation and read/craft cramming sessions, nor (for better or worse) zombie brutes (or hulks depending on how crazy your settings are) personally ambushing you at night on your first few days while you’re trying to read by a candle.
On the flip side, it also makes a ton of interesting changes. Construction suddenly becomes a HUGE part of the game, as players beging to cooperate with each other and try to “rebuild” the world. But then you’ve gotta decide how you want enemy AI to react to that. Zombies will probably attack more in force, and you’ll need to maintain perimeter defenses, invading alien species that are smart will probably try to group up and make coordinated attacks (likely programmed to do so when lots of players are detected active and in the area), etc. Things like farming become more lucrative, and you’ll see players starting to take up roles or jobs in order to get materials/work done for them, and suddenly an economy can form around people’s offline crafting activities… You’ll even see weird stuff like mutants taking up specific tasks like night hunting, or furred mutants seeing after food storage in frozen labs, etc.
But this is kinda what people are trying to tell you here. You actually don’t have a lot of the game’s developers, or developers period, onboard with this idea… And you need them. Lots of them. You need people who have actual coding ability on the boat and willing to go the whole ten miles for this sort of thing, because it’s frankly a huge, HUGE undertaking on a scale that would fundamentally change the game completely. And at that point, the question is do you really want this to be the future of Cataclysm, or do you want another game that’s like Cataclysm but built around an engaging online experience? Because I think the only way an online Cataclysm would survive past very early prototypes would be as a basically new game.
It’d also be an absolute bombshell of groundbreaking gameplay, but with innovation comes struggle and backbreaking work. All this talk is fun and stuff, but someone needs to pick up the tab.