Disclaimer: I do not own Harry Potter, Dungeons and Dragons or a cat.
"Well, turns out we just needed to get through the wall."
"Oh. My. Goodness." Hermione uttered as a sudden realisation hit her. "We can actually go through walls."
"What?" Harry asked, before it dawned on him. "Oh no… forbidden tech alert. What defines a section of wall we can pass through and one we cannot go through?"
"What do you mean?" Marc inquired.
"If someone wanted to move in a direction other than forwards… does whatever magic builds the barrier create a tunnel or merely an entry point and an exit?" Harry explained. "If this magic system is anything like 5e design we probably found a way to travel through walls."
"Wouldn't people use this a lot more often if it worked that way though?" Marc asked.
"It wouldn't be called tech if they did." Harry shrugged.
They gathered their things and got on the train. The other students left their carts at the station in an orderly fashion, but the trio had read through the rules involving them and noted that there was no demand to leave them there. And a bit of spare metal/storage space/objects to transform into better stuff wouldn't go amiss.
They got a few weird looks, but nobody spared them much thought and soon they managed to seal themselves in an empty compartment.
"So uh…" Harry began. "This train ride is supposed to take hours. Let's play a game."
And thus it was decided that they would attempt to run through the Spelljammer adventure Light of Xaryxis. If they didn't manage to do it on the train ride, they'd just bully the Sorting Hat to put them all in the same House so they'd be able to keep playing in the Common Room.
Hermione moved her mechanical pencil over the last page of her character sheet, writing down word after word without needing to stop to think.
"Web… Phantasmal Force…" she muttered, writing down her spell choices. "Harry, are you picking funny horse or should I?"
Harry looked at her with the characteristic expression of an Undead Warlock main staring at an alien.
"Oh, right." she said. "Sorry, I forgor."
"What build are you going with?" Harry asked.
"Haven't done an AbbMind in a while." she replied.
"Hexmind, then." he said, giving her a thumbs-up before going back to his character sheet.
Just then, there was a knock on their carriage door and in walked a blonde princeling flanked by two Hadozee barbarians. Or rather, creatures resembling Hadozee barbarians.
The leader of the gang – if it could be called that – surveyed the compartment with his eyes.
"Have any of you seen Harry Potter?" he asked. "My father said he'd be starting Hogwarts this year too."
"Aye, that'd be me." Harry nodded. "Haven't we met before?"
"Indeed." Draco confirmed. "Have I interrupted something?"
"Not yet." Harry shook his head. "We're about to commit war crimes against space elves in the worst published 5e adventure of 2022."
"But it's 1991…" Draco hesitated, unsure of what to say.
"Trust me, the fact this game is from the future isn't even the weirdest thing about it." Marc told him. "It's way more comprehensible than prestidigicannon."
"You have my attention." Draco said.
"Based." Hermione grinned. "Have a seat and join us, we could use a third player."
Crabbe and Goyle walked off, presumably out of rages already after the first social encounter(which notably does not count towards the expected 6-8 combat encounters explained in the DMG section on creating combat encounters) since you can't expect good resource conservation skill from an unironic melee martial.
Soon afterwards, Draco was struggling to make sense of the atrocity that was the 5th edition Player's Handbook.
"So I can go through walls if I'm abnormal or not an adventurer?" he asked.
"Yep." came the simultaneous answer from all three of his new acquaintances.
"And dragons can breathe through walls?"
"Indeed."
"And walking requires an infinite number of ability checks that the DM is obligated to call for?"
"Unfortunately."
"How does one even play this game?"
At this point Marc pulled a sheet out of his pocket. On it, the words HOUSERULES LIST were elegantly scribed in pencil. Draco took the page and began to read.
1. No creature or object may move through a wall or other solid object unless specifically stated otherwise.
2. Total cover applies to all effects, not just spells.
3. Conjuration Wizard is banned.
4. Creation Bard is banned.
5. Flying races are banned.
6. Nystul's Magic Aura is banned.
7. A summoned creature cannot summon a creature by the same means by which it was summoned, i.e. no infinite simulacrum loops.
8. Genie's Vessel vessels must be nonmagical objects and cannot deal damage or force saving throws.
9. The party may have a maximum instance of one casting of Planar Binding at any given time.
10. Named characters are not eligible for summoning or True Polymorph.
11. Whenever you deal more than 100 damage with a spell, you must turn to the nearest martial player and say "martials lul".
12. Ability checks are only called for if the DM determines that whether or not the character succeeds now is meaningful, otherwise the PC simply succeeds or fails.
"This is genuinely the most sane part of these rules." Draco shook his head in disbelief. "This game had to be written by Muggles."
"It was." Harry nodded. "I wonder if we could start a wizard-run TTRPG company."
"Based." Marc said. "Anyhow, let's get back to the game, shall we?"
And so they finally finished making their characters.
"The adventure begins in a worthless coastal town. I refuse to read this shit ton of boxed text." Marc began. "You're just chilling, minding your own business, when suddenly these weird crystal vines erupt from the ground and people start screaming. A sailor tells you she's heading back to her ship, and you're welcome to join her. Meanwhile, some annoying-looking crystal vines begin approaching, intent on genociding the civilians around you."
Before he could say another word, everyone grabbed their d8s, d4s and d20s, and initiative was rolled.
"We don't even need a battlemap for this, guys." Marc announced. "The encounter is default killable. Harry, your ratbite undeadlock goes first."
"It's morbin time!" Harry grinned. "I'm going to climb the nearest wall and just start EBARBing. EoT."
"Hermione?" Marc asked. "It's your turn."
"I'm gonna use my free misty step from Fey-touched to get onto the nearest balcony and start EBARBing. EoT."
"Your turn, Draco." Marc declared.
"I'm going to wild shape into a panther, climb a tree and take the Dodge action." Draco announced.
"All right, it's a default kill." Marc nodded. "You get a total of 1200 XP, now… four more of those morons approach. 800 XP. And… three more. 600 XP."
They kept slinging cantrips at the endless wave of encounters until one and a half hours of in-game time passed(nowhere near as much in real life as they were just rolling to see how many new blights they managed to kill), and they accumulated enough XP to hit level 20. They then true polymorphed some random street debris into young silver dragons and flew off to find that sailor.
"She looks surprised to see you riding actual bloody dragons…" Marc laughed.
"I'm surprised to see her on foot." Harry shrugged. "Skill issue."
The game finally concluded with the party reaching chapter 3, already halfway through the module after one session. It was at that point that they figured out it would be wise to change into their robes, as they would be arriving soon.
"Firs' years over here!" the loud voice of Hagrid rang out. And so the first-years went over there.
The half-giant led them from Hogsmeade Station, up some stairs and left them in front of the entrance to the Great Hall, where they were greeted by a very stern-looking witch.
Professor McGonagall introduced herself, then explained the merits of each of the four Hogwarts Houses.
"So what do you think?" Marc asked. "Which House is the best?"
"Hufflepuff sounds like a den of Redditors." Harry answered. "The kind of place where you get non-informative answers like 'do whatever you want' that just halt further discussion."
"Gryffindor?" Hermione inquired. "I heard the Headmaster was in that one."
"As were my parents." Harry nodded. "But they seem like the kind of people that call themselves optimizers but dip paladin 2 and think Hexblade dips are good because of w*apons being used with a different stat."
"That leaves the two real Houses." Draco agreed enthusiastically.
"Aye." Harry replied. "I like both of them in concept, but Hogwarts: A History tells me Slytherin has more comfortable chairs and a better table for gaming. Also private rooms for when we don't want others to hear the absolute insanity that goes on in this game."
"The things we do for waifu dice." Marc chuckled.
"At least we're not playing F.A.T.A.L." Hermione said.
"What's..." Draco started.
"No." Harry stopped him. "We do not speak of it. Its existence is merely an academic curiosity."
The children were sent into the Great Hall, and the Sorting Hat began its song. When it finished, the students were called one by one to sit underneath it as it selected a House for them.
"Glugknight, Marc!" was the first to be called to sit under the Hat.
"Oh, dear..." the hat said.
"What's the issue?" Marc inquired in his head.
"I have never been so sad before…" the hat cried. "But now I know that I have no arms and will never be able to pet a floppa."
"Can't you transfer your consciousness into a mech?" Marc asked.
"What do you think I am, some kind of ghost in a machine?" the hat asked.
"You could be, if you wanted to." Marc replied.
"A cunning plan." the hat chuckled. "Off you go to… SLYTHERIN!"
"Granger, Hermione!"
"My goodness… a Muggleborn wanting to go to Slytherin? That's rare." the hat commented. "If you're sure..."
"Of course I'm sure!" she replied. "All the based gamers are going there."
And so the hat cried "SLYTHERIN!" again.
"Malfoy, Draco!"
The Hat just called out "SLYTHERIN!" before he even approached and saved him the trouble.
"Potter, Harry!"
And right away, the whispers started. Harry walked over to the hat and put it on his head.
"I had no clue that the abstract concept of walls was so utterly defunct." the hat sighed. "SLYTHERIN, since you asked."
And there was dead silence for a moment before the Slytherin table began to clap as Harry moved to join his friends.
Shortly afterwards, the feast began, and Harry was pleased to note that he was not being asked a morbillion stupid questions about how he survived Halloween 1981. In addition, the other houses were looking at him like he was the impostor from Among Us(the incredibly popular game from several decades in the future).
Finally, Dumbledore rose from his chair to deliver a start-of-term motivational speech. He raised his right hand in salute, and in a loud booming voice proclaimed:
"Yes Bingus!"
And the whole Great Hall clapped, save for somewhere around ten students. Oh, and also the Slytherins who couldn't be bothered.
"Tax evading moorbounders." Marc gasped in shock. "This means war."