The seeds will fall to the ground when they are ripe, there are often hundreds of seedlings next to a plant. I like to pot up a few to see whether I can produce a new variety!

I agree with Landgirl pot up a few but don't let the rest fall to the ground or you'll have hundreds of seedlings you'll need to remove.

Do they self seed or are you better to take the seed and germinate them in a seedling tray? I want a bed of them and have space for a dozen or more.

I do both taking the seed when ripe and taking self sown ones. You need to take seedlings when they are tiny, even before they have true leaves as they very quickly develop huge roots and they do not like being disturbed. Also when taking the self sown ones I drop them into a bucket of water as I go round, they hate having their roots dry out even for a few minutes.
The seeds are ripe when they are black and the pod is ready to split of its own accord.

Thanks Owdboggy, I shall try growing them.

Thanks for the interesting points, I know what to look for now.

I've never had any seedlings or even seen any seedpods on mine - wonder why?

Which hellebore do you have Stera?