"Can I just have the entire contents of my bedroom, make this place a little homier for research?"

She considers questioning whether every single thing in Bella's bedroom is relevant to the decision-making process and decides that Bella is already picky enough that making her argue about everything she wants is probably not going to be productive in causing her to engage with the process, and summons the entire contents of Bella's bedroom. 

"Cool, thanks. Saves me the trouble of remembering where I left everything." She gathers up her reading material and notebooks and flops on her bed. "Okay, you were going to run through the choice structure for me?"

"Right!" She considers starting with hair, decides that from what she's seen of Bella's personality so far that's not the wisest idea, and goes with, "So, there are two axes on which to make discrete choices about the world. Tech level, and magic level! The tech level options are Faux Medieval, basically a typical sword and sorcery setting or a subdued version of the SCA, Actual Pre-Modern, more historically accurate and not as nice. It requires magic level none or low, and you get a free perk for picking it but it's probably not worth it. Early Modern, basically renaissance up to the locomotive, plus some more modern extra conveniences if you want, like with Faux Medieval. Industrial--you can still add a few conveniences but they're starting to get a bit redundant. Steampunk! Entirely outside your own tech tree, and does not come with any mandatory Victorian social mores, I promise. Contemporary--I don't think I need to describe this too much, you grew up with this tech level, by definition. Cyberpunk--exactly what it sounds like--and Space Opera!" 

"- when a universe is created, does it have the entire implied history?"

"--It has an entire simulated history. If you specify that a genocide occurred fifty years ago then there's a historical record of a genocide, but the people who died in it never actually lived. But if you specify an afterlife, then there will be spirits in it who remember being genocided."

"And if I don't specify an afterlife then everybody who had a relative who survived the genocide would love and miss people who never existed. I mean, I don't see a reason to imply a genocide, but - do you mean the entire simulated history, evolution and all, is it a moral imperative to specify that life in my universe didn't evolve -"

"...I don't know that I would say moral imperative, since you could also stipulate the existence of resurrection. And you could say that life evolved but people didn't. If the latter doesn't suffice for your morals then I strongly recommend that you specify that people are herbivorous." 

"...I can specify that people are herbivorous, gosh, that didn't even occur to me. Maybe I should as long as that happens to be convenient, since probably it is also convenient to make, uh, coconuts that taste like chicken, or something. Okay, maybe life can have evolved but people came to exist as a result of a well specified historical event of some kind not too long ago. Can... I just make everybody immortal?"

"You can make it so that people don't die of old age, you can specify an afterlife and/or resurrection spells, I do not recommend specifying that everyone is biologically incapable of death. That one tends to go badly unless you've exquisitely well-specified the unpleasant edge cases, and the number of people who think they've done so is a lot higher than the number who actually do so."

"Well, can I crib from the people who have successfully pulled it off?"

Genuinely regretful headshake. "Firstly and most importantly, I can only access materials from your world or that have been published by my own organization, and we don't have a dedicated immortality team like we do a world fabrication one. Secondly, I don't know what your standards are for 'genuinely pulled it off'; I know that there are cases where nothing has gone wrong yet, but not many and not how long they've been going." She grimaces. "If you want, I can get you a compilation of ways people have failed, if you don't mind the schadenfreudian tone."

"I will tolerate a schadenfreudian tone. Okay, so I can pick a tech level anywhere from peasant misery to star trek with some detour options ending in 'punk', and I can pick a magic level, and I can go fairly nuts on the details of both, yeah?"

"Right! You'll need to pick the High Magic setting for the kind of robust immortality systems you're looking at."

"Yeah, is there actually any reason not to go for the high magic option, like, are there tradeoffs or pitfalls of some kind there?"

"Being a magic user is a much bigger advantage in a low or medium magic setting. Also, if you go for a no-magic world you get any free perk, but I wouldn't recommend it anyway. Oh, and the High Magic setting means you get the magic user perk for free."

"...advantage at what?"

"Approximately everything. I know it seems petty, but to be fair to them, we do scoop people up right after they've literally died, usually not of natural causes, and most people are more rattled and concerned with their own personal safety than you in the wake of such an experience." Pause. "Especially when it wasn't quick."

"Are you implying that if other people are magical at a high rate I am at a particularly elevated risk of being murdered?"

"You're not at particularly elevated risk of random murder, but we are sending you into a plot of which you are technically the designated villainess. One of the choices you'll be asked to make is between different bad ends for your character to 'canonically' suffer and for you to have to try to avoid."

"Can you elaborate on what 'canonically' here means since you did say the game et al don't exist."

"They're going to counterfactually exist, and you'll remember them. Events will have a tendency to follow their 'canonical' paths, unless you choose the perk 'Off the Rails.'"

"I'll remember them? Broadway musical and all? Does the plot include the part where I design the universe?"

"No--" she pauses and tilts her head. "Well, I suppose if you wanted the plot to involve a mythology where a creator goddess with approximately your personality negotiates with extradimensional powers for the formation of the world, there's nothing that says that can't happen. But by default no. From the point at which you 'wake up' in Villarosa, you will essentially have three merging histories: your life in Villarosa, the life you actually led on Earth plus this," she waves a hand indicating their surroundings, particularly the stacks of historical fiction and worldbuilding guides," "and a counterfactual alternate past in a counterfactual universe where the Villarosa game etcetera existed."

"That's not the kind of game I play, though, I play civ-builders and puzzles. What, in the third of those histories, is causing me to do so?"