Odd ability scores. It wasn't too bad when you needed them for feat requirements, but now? It basically matters for carry capacity and multiclassing.
In my last session, the players in my game found a magic book that could increase Constitution by 1 point. The player who ended up with it was like "great, now I'll have a 15 Con instead of a 14" and it really struck me how bizarre it is that this has no effect whatsoever- even holding your breath is based on your modifier, not your ability score!
How far we've come from AD&D, where even if there was no benefit at all (14 Dex vs. 13 Dex, say), it still mattered for ability and non-weapon proficiency checks!
It starts to make me wonder why ability scores don't just go from 1 to 10, with 5 being +0 and 10 being +5, lol.
I also hate weapon juggling for Clerics- the class is basically intended to do most of it's work up close, and use shields for better AC, but oh no, we can't let them be able to make opportunity attacks and cast spells because "verisimilitude", when the rules can be completely abstract about other things (just in this thread, healing and dying, first aid, inspiring word, crossbow loading...).
You know, actually, I can really just say "I hate how the game designers super duper don't care about realism except when they do." The game is abstract about a lot of things because, well, it's a game, not a simulation. But you constantly run into the strangest things where they're like "but putting on armor has to take a long period of time" while the Fighter and Thief Rogue are bending time with Action Surge and Fast Hands (had this fun discussion a few years ago- a DM was saying "it's going to take 5 minutes for the Rogue to disable this trap" and the player was like, "but I can do it as a bonus action!").
I also hate the weird way bonus action spells worked. Just say you can only cast two leveled spells a turn if that's what you want! I can double fireball with action surge, counterspell an enemy's attempt to counterspell my fireball, and if I have Warcaster, cast Hold Person as an opportunity attack, but oh no, I cast one Healing Word and all I can do is cast Toll the Dead this turn!
-I know this is changed in 2024, but it's stilly silly, because now I can't counter a counterspell on my turn, but i'm free to cast shield when it's not my turn? How does that work!?
Bonus Actions! What are they anyways? How long do they take? Why can I only make one of them? What strange gyrations of reality would prevent me from not taking an action so I could make two bonus actions? How did we go from "you don't really have a bonus action on your turn unless you have an ability that lets you take one" to many characters needing to use a bonus action on their turn as part of their class design? I thought when I switched to bonus action potions that it would make potions used more, but all that happens is now we went from "I can't attack if I use a potion" to "I can't use my off hand attack, flurry of blows, disengage, steady aim, smite, misty step, hunter's mark, hex, if I use a potion"!
Shields being a board you strap to your arm (maybe) to get +2 AC. What kind of shields are they? Why do the rules simultaneously say you hold a shield in your hand (thus you have no free hand and can't carry things) and strap them to your arm (so you can't simply drop a shield in a hurry)? Why do we not have bucklers? Oh so we can streamline the armor charts? But we keep nothingburger armors like ring mail because?!
And weapons! Balearic Slingers were feared during the Punic Wars for their ability to kill soldiers at range, but I can't even kill a goblin with the average d4 bludgeoning damage unless I have a 20 Strength or score a critical hit!
And on that note, why are critical hits so lame for most people, but Rogues, Paladins, and some monsters can pick up a handful of dice and obliterate people 5% of the time? Most of the time, someone in my games will get a critical hit and still do less than maximum regular damage! And even if you do get a good number, wow, I crit for 12 damage instead of 9, but the CR 3 Knight I'm fighting has 52 hit points, so I went from having to hit him 6 times to beat him to...6 times to beat him. Wow!
EDIT: almost forgot. Skill that do almost nothing! I mean sure, great, I can use Medicine to stabilize someone. And then what? How often does Engineering come up? As a DM, I have to go out of my way to create uses for skills just so people occasionally feel better about taking proficiencies that "made sense" for their character, while That Guy who always takes skills that are relevant, is apparently rewarded for having a bland character concept? And don't get me started on tools or gaming sets or musical instruments!
I've lugged around a chessboard for 9 levels with my last character and it didn't matter one bit, lol. And why are musical instruments tools anyways, when we have Perform as a skill? Not that Perform is useful either, mind you, lol.
