I originally started to make a sex system that required the old D6 system to work. Trust me there’s a reason we left the D6 system behind. It did inspire me to come up with this though. I’ve play-tested this a few times at it seems to work pretty well for most situations but I think it need a fresh set of eyes. Note I’ve used pleasure and orgasm as goals here, the language can be flexible, it’s more about a balanced cumulation system that will work to simulate encounters:

Sex can be about pleasure, or power but if you keep going someone’s gunna finish in the end.

Alright roll initiative.

Each creature has a pool of D6 that, when rolled, increase the likelihood of increasing pleasure shown in the table below. Each encounter starts with 1D6 pleasure die for each creature to spend. You can either both work towards adding more to the pool to achieve greater highs (and potentially orgasm) or you can work against it.

(Whilst working against could be non-con it could also be someone just trying to last longer.)

Each character has a sexual ability: Whenever in a sex scene you can choose to add or subtract these values to control the flow of sex (can be implied by actions too if you want it behind the screen!)

0 – Novice/Virgin

2 – Adept

1D6 – Proficient

2D6 – Expert

3D6 – Master

4D6 – Unparalleled

5D6- Godlike

Sometimes you’re not using your raw sexual ability to add or subtract from the pool, you can use your other abilities to the best of your imagination. (If in 5e and using a non-sex skill in a sex scene take its raw ability modifier, half it, and add that many d6s to the pile).

Some creatures can have traits and kinks that increase or decrease the likelihood of pleasure and orgasm, these could be situation specific also.

E.g. Marathon f@*ker – I’m gunna finish and UwU stages have 10 difficulty to achieve for you

Or

Sensitive glands – you finish easily and often, permanent pleasure dice are doubled for you

You can make up whatever you like and run it by your benevolent GM.

I like this because it’s adaptable, any extra roll-playing and you can chuck in or take away a few D6 to reward players for their ideas, and allow people to explore the encounter to the full. Thank for reading this far and any suggestion is, of course, welcome.