I've been toying with this idea for quite a while and, finally, decided to actually try and do it. A proper write-up will be made if there's interest enough for me to open a recruitment thread, this is, basically, just the pitch.
To get it out of the way, if the following things aren't at all your thing, this is unlikely to be the game for you: Futanari and dubious consent (if not outright non-con in certain cases). Those two will, pretty much for certain, be happening. The game is likely to end up in the Non-Con exotic section, if not Extreme.
Other things that are likely, but not definitely certain, to be involved include BDSM, incest and, well, basically anything that isn't gore, snuff, vore or scat.
Those last things are entirely off the table because I just can't handle them. If there's elements that you aren't sure about, let me know, and I'll see with the other players if we can just ... not do that. Except for the futa stuff. That's kinda part of the premise of the game.
Speaking of the premise, the game is, honestly, just a mashup of a game I played, another game I watched, and futanari. If anyone remembers the Orcs and Elves type games, that's how this starts, moving on to, basically, Drake Valentine's The Next Successor - Now With More Dicks!
And yes, it'll be a fantasy-type setting, with pretty much any fantasy race you feel like..
The game begins with the fall of the last independent city to the assembled might of the Futa Empire (name pending). The city falls, and the players, who are either the ruling princesses of other conquered regions or their servants/allies/playthings basically spend the first part of the game having fun with the locals, while the Empress is busy making the next Imperial Princess with the former ruler's wife.
Then the Empress dies and the Princesses have to compete and politic around each other to take her throne. They cannot kill each other off (to prevent coups, each Empress is the central point of a spell that makes her daughters literally unable to harm her, either directly or indirectly (or each other, to a lesser extent. They can't kill each other, or cause lasting damage, but pretty much anything short of that is fair game)) so instead they must either be acknowledged by their siblings - due to affection, logical reasons, blackmail, sexual favours, whatever) or defeat the others in a series of challenges, ranging from physical and mystical to sexual and intellectual.
How things work with the Princesses - they are, legally, in the Empire, sisters, although in reality, they are, at most, half-sisters. Whenever the Empire invaded a place, the Empress at the time would gather up al of the highest-ranking women in the country (or the leader, if that was a woman) and, well, the first one to give birth to a futanari child got to live, and the futa was raised to the princess of that region. The Empire's been going for quite a while, so there's definite branches in this weird family tree. Two Princesses could be half-sisters, or they could be fifth cousins. Some are human. Some are half. Others are barely human at all. The current/previous Empress was mostly halfling - about four feet tall and infamously cunning.
As for gender, the Princesses are all futanari. In the Empire, futanari are the only automatic citizens, although individuals and families can be granted that status, regardless of gender - those who provide noteable service to the Empire, the immediate families of the Princesses, that sort of thing. The older parts of the Empire, for example, are pretty much citizens-only, while in the more recently-conquered areas, men and women both belong to whichever futa claims them and, legally, are property of their new owner. Which means that their owner may do pretty much anything to them, but a random futa would get charged with theft/criminal damage/etc if they did anything to someone else's man/woman.
Since there will be direct (and indirect) player conflict, I'm thinking some form of rules might be preferable to none, but I'll try and keep it light.
I'm tempted by modifying Lasers and Feelings
a little, since it is a very light, simple system.
Also free, which is nice. I like free.
The players would take the rolls of, of course, the Imperial Princesses, their trusted retainers/allies, or a citizen of the doomed city, who will find their old life swept away and need to find a new life under their new masters. Probably quite literally under them.