1) He pulls a sword from a stone.
The idea has merit, but how do we stop everyone else from being able to pull it out as well? Maybe hidden mechanisms that he has to activate? It's probably better if he thinks he accomplished it by himself. If we're going to tell everyone that he's the rightful King, he has to believe it too. Maybe I'd activate the hidden mechanisms, then?
2) He overthrows the evil tyrant, freeing the citizens from their sorrow and oppression.
An emphatic NO. My Lord isn't actually a tyrant, as such. Besides, if he were just overthrown all of sudden, I think people would be more bewildered than joyful. Besides, this is only a good idea if we want a King with sharp, metal things protruding from vital parts of his anatomy.
3) He defeats the beast which has been plaguing the city, freeing... etc.
Probably not. There is no beast, and even if we had one brought in, any monster that was weak enough for the King to defeat wouldn't last long in a city like Ankh-Morpork. No doubt angry merchants and irate bartenders would have it outside the gates in a matter of minutes. Also, freeing the city from a beast that arrived yesterday probably won't earn as much gratitude as we're hoping for. On the other hand, patience is key, something I learned from my Lord himself (ironic that his wisdom should come up now, while I'm plotting to overthrow his reign). Setting the beast upon the town and waiting a few weeks could work. Even a few months or a year would be fine.
4) He rescues the princess from great peril (thus freeing her from...).
Problem: there is no princess. People might believe there was one if we told them so, but even then, if they don't know first-hand how blindingly fair and (most importantly) generous she is, why should they care whether she's rescued or eaten? (In fact they might prefer it if she died a gruesome death, the more gore the better. Everybody loves a show. They might even pay for tickets.)
5) He conquers all our enemies, even if they didn't know they were enemies, and brings to Ankh-Morpork an age of peace and prosperity.
Well, technically speaking, my Lord has already done this, only with fewer battles and more diplomacy than fairytales would lead one to expect. If anyone else did this, it would probably involve a great war of some sort, lots of deaths, and bitter old veterans. Probably not the way to go.
Of course the best option would be for him to be born into the royal family, with the royal blood flowing through his veins, but we'll just have to make do with what we have. Out of these options, probably the first one would work the best. I just need some sort of stone that attaches to the sword... I heard that Leonard da Quirm was quite ingenious at creating interesting new devices. I'll ask around and make an appointment to see him sometime this week.
My Lord has been in one of his Moods lately. As always, the term is relative - it's hardly noticeable unless you're watching, which the entire staff is - but it's as if the rather expensive floor tiles have turned into eggshells, and the walls into flimsy rice paper. The maids all hurry outside during breaks to gasp for the air they had been afraid to breathe in on shift, in case the rice paper walls blew in from all the excess respiration or, worse, in case my Lord decided to be sarcastic at them about it.
It's not even as if my Lord has been particularly nasty lately. In fact, he's been positively nice. He keeps asking people how they're feeling. Several maids have decided that they couldn't take it anymore, and now I have a folder full of resignation letters.