My setting has technology more-or-less equivalent to Earth's 17th century, and a big chunk of my inspiration is Neal Stephenson's Baroque Cycle. The books detail the steps that led to the industrial revolution so my setting also has similar early tech, aided by magic of course.

(Airships, for example, use magic derived from Resilient Sphere to make their balloons supernaturally rigid and impermeable, then instead of filling it with a lifting gas they just evacuate all air from it. Their hulls look like solid wood but they are instead a honeycomb structure made of giant spider silk sandwiched between thin wooden veneers to keep the cold air out, and reinforced with the occasional mithral spar. The propulsion is purely magic though, the props are powered by aetherosiphon engines. There are some secret military projects aimed at creating a fully-pressurized heavier-than-air skyship that can actually fly over the taller mountain ranges; since their passenger compartment is not pressurized, a standard skyship's maximal cruising altitude is 3-3.5 kilometers while a trained military crew can maybe get up to 4.5 km.)

I have my own language mappings in my homebrew. Most of them only appear as names since most people speak Common, but I did include some people in my game who don't. (I make sure that they are some who speak a language that I speak too.) So the mappings are:

1. Common - English. We're playing in English, duh. (Before contact with Elves, humans spoke "proto-Common" which would be mapped to German if I had to use it. Many humans still have German names.)
2. (High) Elvish - French. Yes, in-universe the Common language has plenty of Elvish influence. (Classical Elvish is Latin.)
3. (Wood) Elvish - Greek. Most Wood Elves speak High Elvish, but their names are Greek and many of them still speak their own language as well. The continents and seas are often named in Ancient Wood-Elvish (i.e., classical Greek) because they used to be the primary explorers before the rise of the High Elves.
4. Dwarvish - modern Dwarvish is Norwegian, old Dwarvish is Icelandic.
5. Halfling - Frisian. (Fortunately I haven't had to say anything in Halfling so far.)
6. Gnomish - Welsh. (Again, fortunately I haven't had to say anything in Gnomish yet.)
7. Orc - Russian.
8. Goblin - Mongolian.
9. Tellurian (not a species, but an influential country) - Spanish. Many people alongside the Bay of Luria speak Tellurian as their native language instead of Common or their racial language.
10. Sylvan - Finnish. (My go-to for weirder names as well. Many Fey-related creatures have Finnish names, as well as those who live near Fey portals.)
11. Giant - Hungarian. (They feature a lot in Hungarian folk tales.)
12. Draconic - Hindi.
13. Hashiman (not a species, but a group of eight islands - though they are also the Kenku homeland so most Kenku speak this as their native language) - Japanese-ish. The language comes in two dialects, Hanego which is used primarily by Kenku but also Aaracokra, Owlin, Tortles, and other creatures with hard beaks that have difficulty pronouncing M and N, and Hadago which is used by the rest. They are identical in writing, differ mostly in pronouncing those sounds.

If we're about to simulate physics, the wooden stick would turn into an expanding cloud of plasma about halfway through the "railgun" anyway.

Evil DM: the bookcase is also a mimic.

Yeah, there's a ridiculous imbalance.

And then you start DMing, even as a beginner who has no idea what he's doing you get 6-8 players at the table, that party size is unsupported by the balancing tools given by WotC so you wrack your brain trying to come up with challenging encounters for the whole group, burn out, stop DMing, and the imbalance worsens even further.

TBF the only class that gets more than one extra attack is the fighter.

Now of course it would make sense to sum up the levels you have in classes that get multiattack, and if you have >=5, you get an extra attack. But since attack progression is far less regular than spell slot progression, getting something approaching regularity beyond that would be difficult.

Now if OneD&D wanted to boost martials and introduce some sort of a multiattack scaling across multiclassing, here is how that could work:

1. Introduce features called Special Attack and Signature Attack. (Simply because just stacking extra attacks in a way that gives a bunch of half-casters extra attack at level 5-6 would give full martials a ridiculous number of attacks per turn at higher levels.) Special Attack is an attack that deals double weapon damage (which stacks with crits), but other extra damage sources like smites don't get doubled. Signature Attack is a Special Attack that can also force a save, either a STR save vs. being disarmed, a DEX save vs. being knocked prone, or a CON save vs. being dazed. You pick which one when you get the feature, and you can change it on level up.
2. Introduce an attack progression table which details how many regular and special attacks you get per warrior level. (IDK if Lemmy's MD syntax allows tables in lists, so see the table below.)
3. Like for spell slots, some classes (fighter, barbarian, monk) count as whole classes, others (paladin, ranger, artificer) count as half, and some caster subclasses (bladesinger, swords bard, hexblade, etc...) count as third.

The table:

So:

• A level 12 single class fighter gets 1 normal, 1 special, and 1 signature attacks.
• So does a fighter 6 / barbarian 6.
• A level 12 paladin counts as a level 6 warrior so they get a normal and a special attack. (Also, in OneD&D the divine smite is a bonus action spell like every other smite, so the level 18 paladin can't go too nuclear with 3 smites per turn.)
• A fighter 6 / paladin 6 counts as a level 9 warrior, 2 normal attacks and 1 special attack.

Of course this could be refined a bit further, e.g., instead of a generic "special attack" they could pick power attack (must be a strength-based attack), precise strike (must be a dexterity-based melee attack), or pinpoint shot (must be a dexterity-based ranged attack) and they could swap this one on level-ups too. But I think this should be a start.

Look, you spring a door mimic on them just once...

"As the size of an explosion increases, the number of social situations it is incapable of solving approaches zero."

Not really, it replaces the attack stat with the spellcasting stat, kind of like shillelagh but only for a single attack, and then stacks some radiant damage on it at higher levels (+1d6 from level 5 then cantrip leveling). It can also replace the damage type with radiant. Useful for any weapon-using caster class that doesn't get multiattack:

• Clerics would be a great target audience for this, except it's not on their spell list. *sigh* Magic Initiate (Druid) it is.
• It could be useful for non-hexblade warlocks too.
• It's a great damaging cantrip for bards who severely lack those.
• It's good for even a sorcerer or a wizard, it turns the light crossbow into a long-range radiant-damage cantrip.
• Arcane tricksters: could be useful depending on the build, probably pairs really well with a headband of intellect. (Edit: Or an extremely INT-focused Arcane Trickster with a 2-level wizard dip for the bladesong.)
• Eldritch knights: really useful at levels 1-4 if you're running into some monster that resists or is straight-up immune to nonmagical damage. Markedly decreases in usefulness once you get multiattack and/or a magic weapon.
• Probably good for artillerist artificers (they are not in the UA so it's unknown whether they'll get this cantrip), might be good for alchemists, OK for battlesmiths until they get multiattack, and redundant for armorers.

How I'd improve it further:

1. Make its casting time 1 attack and limit it to once per turn in the fluff. That way it stays useful for eldritch knights, ~~bladesingers~~ (scratch that, bladesingers can cast this in place of an attack already), valor and swords bards, and the two multiattacking artificers (less so for the armorers, but even then, it gets them a good ranged attack in a guardian suit or a good melee attack in the infiltrator).
2. Add it to the cleric spell list. They are the full casters most likely to go into melee even without the multiattack.

Yeah, he was a condescending sexist prick to the Kiyoshi warriors (initially), and while it did earn him some beatings, it didn't get him a restraining order and he even got with Suki in the end. That's high CHA alright.

I have a 10-page summary of the rise and fall of the Third Civilization, starting from the Soul War ~500 000 years ago, then the Age of the Giant Kings, the Curse of Forgetting, the antique era, the Age of Conquest, the Dark Age, the Empire of the Diamond Vault, the Arcane Age and the Ascendancy Period, and finally the Collapse.

The game takes place in the Fourth Civilization, 10 000 years after the Collapse.

If one of my players can't make it and it's not possible to remove their character from the group storywise (meaning I'll have to control their character in combat), the character will immediately equip the "Talisman of Protection from DM Stupidity". What it does is:

• When a character holding this item dies, they fall unconscious instead and disappear into a demiplane. While in this demiplane, the character is stable at 0 hit points. When the party takes a long rest, the character will reappear near a random other player character as if they had also taken a long rest.
• If the player retakes control of the character while they are still in the demiplane, the character reappears next to another player character of their choice with 1 hit point.
• If all other player characters die, the character in the demiplane will die too. If the method of their original death would have left a corpse, the corpse will reappear adjacent to a random player character's body. Otherwise, they will disappear alongside the demiplane.

Basically, it makes them immortal unless a TPK happens.