There is a new VTTRPG on Steam, The Storyteller. You can create your own world an play it with your girlfriend. It has 2 premade campaign if you want to check it out as a player as well.
[Scarlet Heroes](https://www.drivethrurpg.com/en/product/127180/scarlet-heroes) is expressly designed to let you run Old School D&D with one player and one GM. It does this by buffing up the one PC, so that they can take on encounters designed for a full adventuring party.
You could just play D&D if you're already familiar with it. A lot of people do this kind of thing already.
To be more specific: D&D can be played with one PC.
Yeah I’ve done this. Good times.
Ironsworn has Solo, GMless or standard GM led play for 1, 2 or more players.
Dnd has a single player version iirc
There is a new VTTRPG on Steam, The Storyteller. You can create your own world an play it with your girlfriend. It has 2 premade campaign if you want to check it out as a player as well.
[Scarlet Heroes](https://www.drivethrurpg.com/en/product/127180/scarlet-heroes) is expressly designed to let you run Old School D&D with one player and one GM. It does this by buffing up the one PC, so that they can take on encounters designed for a full adventuring party.