There is no application form for the Royal Family. No interview, no appeal, few in the way of entrances or exits. It is that strange lottery, an accident of birth.
But to stay royal you have to do two things. Serve, and survive.
You have to do some service. Some of it ceremonial, and often dull. Some of it - if it involves celebrities or travel - less dull. A lot of it is woven into the civic life of the UK - openings, namings, lunches and dinners.
You have to survive. You have to aid - and certainly not threaten - the survival of the House of Windsor and the British monarchy.
It's not a bad life. It is a constrained life, often unchosen. In exchange for a pretty comfortable standard of living in perpetuity, you lose a lot of choice.
But you must do these two things if you want to remain a royal.
And it's not clear that the Duke and Duchess of Sussex really want to do either.
In Sandringham later the players will receive a series of options, a range of possibilities.
These will be based on the stated aim of Prince Harry and Meghan that they want financial independence, to take paid employment, to spend a lot more time outside the UK, to exclude the media from their lives at their discretion and to continue at least in part, a royal life, service to the Queen.
Leaving aside the heady brew of contradictions detailed elsewhere, the balancing of these different aims and demands is hard enough. Money is a big issue.
But so will be the status of the court of Prince Harry and Meghan that emerges. Will it be entirely independent of the palace, of the monarchy? Will the palace retain any veto on direction or projects for the couple?
Much, says one official, depends on how much royal work the prince and Meghan intend to do, and where.
To watch Prince Harry for not very long, as I have, is to observe a man who comes alive with crowds, with love, with those who need him.
But also to see a man entirely unhappy with his lot. A man who desperately wants to get away from cameras, observers, outsiders, looking and filming and exploiting him.
Now the prince, who has worn the nation's uniform in combat and amongst death and injury, is openly sneered at across pages and feeds and memes. It is hardly a great national moment.
Prince Harry has had a hard time, from when his mother was taken from him, a boy aged 12. It is important to remember also because it demolishes the Meghan Myth - that somehow she is the root of all today's turmoil.
The Meghan Myth is nonsense, with a generous sprinkling of spite, misogyny and some racism. The prince always wanted out. And together, with her brains and understanding and love, they think they have a way.
Maybe a deal comes on Monday, Tuesday, Wednesday. But what are not up for negotiation are service and survival. Both must be observed by Prince Harry and Meghan if they are to remain royals.
'Looking for exit'
Perhaps Prince Harry's allergy to media coverage can be managed at those royal events and duties he attends. Perhaps the couple will make themselves available to a significant and visible degree of service.
But the style of their departure from familial obligation, their declaration of independence last week, was so abrupt and so disrespectful.
The duke has gone beyond rebellious prince. Meghan, the enabler, is in Canada, with child and dogs. That degree of going rogue looks quite a lot like a direct threat to the survival of the monarchy.
That is why today's meeting is hard.
Maybe the two sides can strike a deal over the next day, two days, invent a new structure that officials say might be emulated for a new royal generation.
But will the couple really agree to the restrictions that service and survival demand?
A deal will probably be crafted - however the direction of travel is one way. Prince Harry and Meghan are looking for the exit.