Game creator Garry Newman (he of Garry’s Mod fame) explains:
Like tallness, face, head size, jaw definition, race, and limb size, penises are also randomized.
When you load the game for the first time, you are allocated an (unchangeable) body, complete with face, skin tone and genitalia. While Newman hasn’t gone into any detail, it’s now been revealed that this is tied in – somehow – to your unique Steam ID. Want to see it “in action”, so to speak? Here is a short NSFW video – as spotted on Reddit (where else?) – showing some of the variations that are available.
And yes, right now, all of this is relating to male genitalia, but the studio’s working on that, too. A recent blog post reveals that developer Facepunch has started creating a female model for the game – and she won’t be “pretty”.
We really don’t want to make the female model unrealistic in the sense of her being aesthetically idealized. In the same way that our male models aren’t perfect specimens of the male body, neither should the female be. No huge boobs nor four-inch waists here.
The in-game penises are visible right now if you remove your character’s clothing (or just don’t put any on), and female character models could appear in Rust as soon as this week, if we’re lucky.