Healing potions as a bonus action was a terrible idea

Responded to someone's question about this, realised it should be its own thread - people keep misunderstanding what I mean when I say that changes like that were actually terrible for the game, as they exist to plaster over basic issues with the game. There's a paragraph explanation right below this if you want a TLDR, if you want the long form keep reading after that.

SINGLE PARAGRAPH EXPLANATION BELOW

Bonus actions in D&D 5e serve two conflicting purposes: class-specific mechanics such as rogues' frequent use of bonus actions for core abilities and general-purpose actions such as racial abilities or consuming potions. This creates imbalance, as classes reliant on bonus actions are penalized when required to use them for non-class abilities, while others are unaffected. Healing mechanics are flawed due to weak, spell-based healing that incentivizes "yo-yo healing," where players only heal allies after they drop to 0 HP. This approach feels unsatisfying, reduces combat resilience, and complicates encounter design by making players more vulnerable to bad rolls or poor positioning. Scalable, non-spell healing would address these issues by increasing individual resilience without inflating total party health or incentivizing undesirable playstyle. Combined, these make their only real change being you can now drink healing potions as a bonus action a ridiculously lazy bandaid fix, given that after ten years they really should have solved the structural issues instead.

SINGLE PARAGRAPH EXPLANATION ABOVE

Longer explanation:

Bonus actions are a comparatively simple explanation. Their ancestor is 3.5's swift action, once they realised that wizards using quicken magic to cast spells as a free action probably needed a limit on it, so those and other "free but we don't want you stacking them" kinds of things like changing stances took a swift action. In 4e this was formalised into the standard>move>minor action system, with any of the bigger actions being convertible into a smaller one, like taking two move actions instead of a move and a standard or a second minor (swift/bonus) action instead of a move. These actions were always clear about what they wanted to do.

But 5e, in all its wisdom, combined two different kinds of action into the bonus action, which causes gameplay issues that never needed to exist. The first kind of action is "action but smaller, that you choose between just like you do with actions". For instance as a rogue using disengage, hide, steady aim, dash or a bonus action attack. In this context, the bonus action works the same way an action does, just smaller. It's part of your class kit, you're supposed to be picking one every round. And that's fine! PF2e does something very similar, but far more cleanly, with its three action system.

Unfortunately that same bonus action is also used for class agnostic stuff like a harengon leaping or keenness of the stone giant, stuff that is expected to be a "bonus" that is done in addition to whatever you were going to do this turn but naturally need to take some kind of action so you can't do a bunch at once - the stuff 3.5 invented the swift action for. The result is, now that stuff like raging and smiting shares an action with them instead of just being part of doing other things like they were when swift actions were invented, two entirely different types of action are competing for space. Which would be an acceptable, if clunky, set of choices - if every class got the same mileage out of the first use, but they don't.

Why is that a bad thing? Because they aren't balanced against each other, at all. There's a temptation to go "but of course they balanced around that!", but that's an utter lie. A rogue is balanced around using their bonus action every round, a wizard is balanced around their class rarely needing to use one. Therefore if a rogue drinks a potion it takes away a goodly chunk of what they were going to do that turn (they needed that bonus action to hide or whatever), while a wizard loses nothing since they use bonus actions for the occasional bonus thing rather than being built around using them every turn like a monk does. To claim WotC is balancing around that you will need to claim, with a straight face, that a rogue not using their bonus action is equal in balance to a wizard in combat usefulness.

And the potion thing leads us to healing. I've already explained why having combat staying power tied to an action type that some classes are balanced around using for other things and some aren't is dumb and the mere sentence "tying combat staying power to use of a purchased consumable in a game where they didn't even try to get economy and expected player wealth functioning" should answer why that's a bad idea by itself, so let's move on from potions to other healing mechanics. The basic problem is that using spells to heal is goddamn stupid, game design wise. This isn't an MMO with unlimited mana so you can balance specialisations around being a healbot, classes like clerics have one big pool of resources (spell slots) to use to influence the world and once they're used up they are done. Since a huge amount of players don't enjoy being a healbot, you'll have noticed players deciding with a sigh that someone should have healing spells, as a game designer the last thing you want to be doing is incentivising a playstyle people won't enjoy. Which they realised, making 5e, which is why they deliberately made spells like cure wounds much worse.

Now, a lot of people mistake that for meaning there shouldn't be healers. Healing is a valid archetype - hell, support as a whole is, which is why it's a pity 5e removed most support classes and made the existing ones much less support-y. People who want to do that should be able to, and in general access to good healing is incredibly good for gameplay. Why? Because with access to bad healing, especially bad healing with a lot of use (cough, healing word), 5e combat has a habit of turning into yo-yo healing. If you're healing someone for 8hp and they're going to take 30, if they're on 15 you may as well not heal them. The smarter move is to wait until they hit 0, then heal them - that way they're on 8 after you've healed, not on 0 like they would be if you'd healed pre-emptively. In addition to being degenerate gameplay, that also feels bad as a healer, healers playing one want their heals to matter.

Then why not make healing with spells better? Because it's too repeatable. If it's both good and repeatable, that means players who don't particularly want to are incentivised to spend their turn doing absolutely nothing except reducing their ability to do fun shit later in the day. Again, this isn't an MMO - that playstyle works in other games, but spending turn after turn healing over and over is not how a TTRPG should work. But that means in 5e we're left with healing that is too weak to actually save anyone, which also makes encounter design way harder for a DM, since resilience to variance drops as potential player health as a proportion of potential party health does.

To illustrate this, picture 5 players have 100hp each. This means if one player ends up in a bad position (remember that in 5e players have significantly less counter play available, so this can happen in ways as simple as rolling badly on a single saving throw), 100 damage, or 20% of the party's maximum health, is enough to drop a player from the fight.

This doesn't sound like too bad a thing - actions have consequences, right? - until you stop and examine it further. 20% of a party's HP is not actually that much, combat is ostensibly balanced around 3 round fights so in one against monsters of equal capability to the players, they'll be doing 33% of the party's total HP a round. I don't think this actually happens much (just as the often espoused 6-8 encounter day doesn't), so drop it to 20% for a 5 round fight. This is still enough to completely down a party member, so let me show you an alternative. Imagine a universe in which half of your damage taken can be transferred at will to other party members - the HP pool is now 500, but now 200 damage must be done before anyone goes down. Healing works in much the same way - if you can heal 100 damage, the effective party HP pool is 600, but an individual party member can now take 200 damage before going down.

The reason this is desirable is because as stated, it's really easy for someone to go down. If that happens the DM is often having to choose between verisimilitude (obviously the lich should have his minions execute the player so he doesn't get healed and stand up next round) and player fun (oops, you failed one roll, character is dead) and more specifically, the entire fight is now centering around the rogue who got unlucky and ate an early hit so will now spend the entire combat hovering around 0hp. It also improves play in general - you want a single player to be able to take a goodly proportion of the damage the entire party can, it means the DM doesn't have to arbitrarily have each foe attack a different player. And you want to do that without raising the total pool of damage that can be taken too much - you make the effective HP pool 1000, either by giving each player 200 health or by allowing 500 points of healing to be distributed amongst the 100hp players, you've just doubled their defensive capability.

Which is why I said that you want potential player health to be as high a proportion of the party's collective potential health as you can, for a DM there are nothing but upsides in encounter design. So, say we're balancing around 500hp - how do we do that? Logically what we want to do is ensure each player has say 60hp, and there is 200hp of convenient healing available, now we're at that same 500 maximum but it takes 260 before anyone goes down. We can't achieve that with spells, because either you're now balancing around some classes spending all their slots healing (bad, as discussed before) or you aren't, and if you aren't that means you're balancing around them only using a few, and that means they can instead use all of them to blow through an encounter because unlike normal spells which are limited by fight duration, these extend the fight's duration. So now early fights are never lethal unless they're ridiculously party killing lethal, and no danger or TPK is a bad binary.

Before we go onto the alternatives, I should mention that HP pool issue is one 5e deliberately caused with hit dice. 4e had lower health totals, but higher healing totals - hit dice come from 4e's healing surges, which were 25% of a player's health. Players could spend them during rests to heal, 5e style, and players could second wind as an action in combat to use one, with different classes having different amounts. A wizard's baseline was 6 (so 150% of their health a day, but a lower health pool, as opposed to the flat 100% all 5e classes have) while a fighter's was 9 (so 225% of their health a day). The flat 25% meant they scaled much more usefully, the party's thief rogue with the healer feat was using their bonus action to heal 1d8+3 when players had 27HP and now that they have 115HP, the rogue is healing... 1d8+3. It's added a huge scaling issue for absolutely no reason.

Especially because the answer is that healing should be powerful (able to meaningfully rescue a downed or nearly downed player, increase potential individual health as a proportion of potential party health), which as discussed it can't be as a commonly available spell, it would only be balanced on a level 6+ spell. So the answer therefore is non spell healing, for which healing surges made an ideal basis due to their scaling and hit dice do not. There are a few useful sources in 5e, and you'll notice those feel good - a paladin can rush in, fully heal a downed wizard with lay on hands, and get on with the fight. It doesn't take away from a pool of resources they need for other things, they can't smite less for having done so, and unlike a spell slot the wizard is actually rescued, not hovering around 0hp like the rogue before but actually able to continue the fight.

So the player gets a big and meaningful moment, the DM doesn't have to constantly worry about evenly apportioning damage, and the fact that it's from a limited pool means overall player health hasn't increased that much and fights aren't a slugfest. That is way, way healthier for the game, but instead for 5.5 what happened is they forgot why they nerfed healing spells in the first place and buffed them a little instead of just making sure spell healing was shit or nonexistent and increasing sources of non spell healing. Now, to be sure, it's harder to do. Last edition support classes like bard and cleric could, 2-3 times a short rest as a bonus action, have a target spend one healing surge (25% of their health) and heal an extra 1d6-6d6, depending on level. Can't do abilities like that any more because hit dice don't scale, you'd have to fiddle with spending a certain amount of hit dice per level.

Just to reiterate, since people often misunderstand, this isn't saying life cleric shouldn't be available to those who want it. It's saying life cleric should suck with healing spells because everyone should, low level healing spells are a sacred cow that hurts combat and class design. But they should have access to strong, but limited, non spell based healing, and there should be other sources available, especially in the form of things like second wind being given back to players. I say especially class agnostic methods because if healing is genuinely good, then it needs a second limiter other than just the class or subclass doing it not being able to often - you want a reason to not stack those classes, and a way to function without them. So something like them being based on healing surges (or 5e's "we'll take this and just kind of make it worse", hit dice) is an additional lever to balance around because it means just making 5 healers isn't incentivised since the target you're healing will just run out of hit dice if you do that.

The dumbest aspect of all this is these are issues they identified long ago, spent ages considering how to solve for 4e, and along with stuff like how to make tanking work game up with simple, elegant fixes that were carefully constructed to solve the gameplay issues these represented. Granted, they then fucked a bunch of other stuff up, I could write a post just as long as this about what 4e got wrong, but what it got wrong was stuff unrelated to any of this. And I'm not saying 4e's solutions should be used, just that it's an example of them already identifying and fixing these exact issues. Then for 5e they just... didn't bother. And have continued not to bother, 5e has so much incredibly lazy content, and for 5.5 they were just like "yeah make even more stuff a bonus action, including healing potions, and chuck an extra die on cure wounds and healing word". After a decade, that's all they came up with. Bandaid fixes that did nothing to cover the actual structural issues they built in for no reason.