This story has already been completely written and will be updated every few days or whenever I feel like it. It's 17 chapters long but I might add in one more. All the chapters are about 1000 to 2000 words long.
A bit of context: Morgana is good and has married and moved away from Camelot. Arthur is king, has not lifted the ban on magic yet, and does not know of Merlin or Morgana's magic.
Merlin threw open the curtains and let in the sunlight as he had almost every day for the past ten years. And as such, he knew just when the pillow would come flying at him. Today he caught it and threw it back towards the bed, but not at the king himself. Merlin walked to Arthur's side to pull the blankets off of his king, not caring about the sputtering protests he received.
Merlin wasn't in the mood for banter this morning due to sheer exhaustion. He had spent the whole of the day before helping with preparing for the upcoming arrival of the Lady Morgana and her new husband, Lord Urien, for her birthday celebration, as well as making deliveries for Gaius, and all of his normal duties as Arthur's manservant.
Arthur grumbled as he stood to get out of bed and let himself be dressed by Merlin. The king sat at his table to eat the breakfast Merlin had laid out for him, now somewhat awake. Merlin leaned forward to fill his goblet with water and promptly dropped the pitcher onto the table, spilling the water in every direction.
"Merlin!" Arthur yelped.
"Sorry, Sire." Merlin quickly righted the pitcher before grabbing a clean rag from the laundry basket he had brought up that morning. Arthur jumped out of his chair before some of the water could spill over the edge of the table and onto him, moving out of the way so Merlin could clean it up.
"By the gods Merlin, can't you do anything right?" Arthur commented, his usual insults annoying Merlin even more than usual.
Merlin didn't respond, his weariness preventing him from raising to the bait and engaging in any banter. He swiftly began mopping up the liquid, but it was soon clear that one rag would not be enough to soak up the amount he had spilled. The manservant murmured an expletive.
"What are you doing? Just clean it up Merlin, it's not that hard!"
Merlin stopped his scrubbing and turned to eye the king. "If it's so easy, then you do it." Without thinking of what he was doing, Merlin threw the wet rag at Arthur's feet with a splattering sound. "I challenge you."
It was meant to be a challenge for the king to do something himself for once, but Merlin knew that wasn't what he made it sound like. The implications made no sense. A challenge was between two knights, mostly over matters of honor, not between a servant and his master. A gauntlet was thrown and picked up, not a dirty rag; this challenge meant nothing and they both knew it. Merlin was prepared for the mocking Arthur would surely start.
"You're not a knight, you can't make challenges, Merlin." And there began the mocking.
It was too late to stop Arthur's snarky remarks, so he might as well stick to his convictions, he had nothing to lose by making this as bad as possible and pushing the dumb idea he had just made up. "A servant's challenge, then. Go on, pick it up." Merlin goaded, meeting Arthur's eye, more serious than his normal cheerfulness in his sleep deprived state.
"And what, pray tell, is a servant's challenge, Merlin?" Arthur crossed his arms, eyeing Merlin disbelievingly and calling the other man's bluff.
Merlin stayed silent, thinking for a moment on what in all of Albion a challenge called a servant's challenge could entail. An idea began to form, and he gestured in between himself and the king, "We switch places. You try to do my job and be a servant for a whole day and if you can do it without any major screwups, I'll not complain about a single thing for a whole week."
"While I admit the idea of not having to hear you complain for a full week is appealing, what is it you will be doing during the time I'm doing your job? Slacking off?" Arthur scoffed, seeming to think this was somehow a plan for Merlin to shirk his duties for a full day.
"I'll do your job." Merlin grinned somewhat wickedly. "I'll run the kingdom."
"Even if I accepted your challenge, I can't just let you run the kingdom Merlin."
"Why not? It's not like it's that hard." Merlin threw the king's words back at him. "And you can have Leon or Gwen step in if I do something too stupid. It's not as if I have no idea what you do, you know. I've watched you do it all this time." Merlin's words were beginning to sound more confident and less like he was improvising them on the spot.
Arthur narrowed his eyes. "So, if I win, you'll not complain for a full week. What would happen if I lost, not that I even could, but for the sake of argument, what would you win?"
Merlin started for a moment, he had thought the bragging rights should he win would be plenty, enough to last him possibly forever, but Arthur seemed to be actually considering accepting the asinine challenge he had made up and the king sounded as if he might be willing to give up something greater.
"If I win, you'll give the entire serving staff a pay raise." It was a bold move, but they certainly deserved better pay and hopefully Arthur's work as a servant would make him realize it.
"If I have the chance to lose that much then you have to wager more. If I win you have to go a whole month without any complaining." Arthur negotiated.
Merlin pushed back, unsure of where the idea came from, "Then you have to be a servant on a feast day."
Arthur looked his manservant in the eye, respecting that he had not backed down. "Then we have a deal." Arthur leaned down and picked up the rag Merlin had thrown.
Merlin's eyes widened. He really hadn't expected Arthur to take him up on his challenge, he was just trying to prove a point.
Arthur grinned, slightly threateningly, as if he were already assured of his win and interrupted the silent shock Merlin was going through. "We'll have to make a few more rules for your little challenge, but I do believe I need to plan a feast."
That evening Arthur and Merlin sat down to flesh out the rules for the challenge.
"We already have the perfect feast planned and ready. Your sister is coming next week; there will be no foreign dignitaries to embarrass the kingdom in front of and she won't murder you if we do it another time where she isn't there to witness it."
"Merlin," Arthur scowled, but Merlin gave him a look and the king deflated slightly, admitting the truth to his words. Morgana would end his life if she was not given the opportunity of seeing Arthur masquerade as a servant for a day. "We'll have to make up schedules for each other beforehand, I can't afford to have you miss something important because you forgot about it."
It was Merlin's turn to scowl. "My schedule is entirely based on yours, Sire, so if you can write up one for me, I can make a complementary one for you." Arthur nodded in agreement, ignoring Merlin's snarky tone. He wrote down the word 'schedules' on a scrap piece of parchment he had fished out of his desk.
"I'll also need to write out a set of rules for you; I can't have you insulting half the citizens by saying something dumb."
"Then I shall do the same for you." Merlin gave him a tight-lipped smile; he didn't appreciate the patronizing tone the king was giving him. "You'll also have to spend the night before in my room in Gaius' chambers."
"What?! That wasn't part of the deal."
"How can you be a servant if you're holed up in your fancy chambers in your expensive bed? Plus if you stay in here, you won't wake up on time and you'll have no way to get breakfast. If you stay in the physician chambers, Gaius can wake you if you oversleep and he'll make sure you get something to eat."
"I have to eat like you too?" Arthur looked at Merlin with distaste. Merlin just rolled his eyes in response.
"You won't have time to get anything from the kitchens anyways, so it's that or nothing."
"You'll of course have to wear the full formal outfit for all the meetings." Arthur changed the subject, not so subtly trying to gain the better footing. "Full chainmail for training, the formal outfit for the council meeting."
Merlin groaned. He, for some reason, did in fact have a set of chainmail made to fit him. It wasn't specifically made for him, or so Arthur said, but it was certainly too small for any of the knights and Arthur had made sure Merlin had used it a time or two.
Arthur grinned in smug satisfaction.
They concluded their meeting, Arthur agreeing to have a schedule and a list of rules made up by the following day, Merlin prepared to make his own schedule and rules by the day after, and both promising to meet in Arthur's rooms again to review the lists.