Across all of the various rules and features and traits and spells and feats (and so on), there are a plethora of unique mechanics. Some are used repeatedly and show up in multiple different classes and other features, while others maybe show up once and dont get much more attention. What are some mechanics you wish were used more in game design? 

As my own examples:

1) Random Effects Tables for Bards. With the introduction of the College of Spirits Bard from Van Richten's Guide to everything, the subclass featured a unique "wild magic"-esque table of different effects which come from their "tales." What sets this table apart is that it scales with the bard's inspiration die. So the table naturally grows and gets more powerful possible effects as the bard levels up. I would love to see more Bard subclasses that use the Bardic Inspiration die in unique ways like this

2) Damage Threshold. This shows up alot for larger items and vehicles, but Id love to see some sort of Damage Threshold mechanic that is accessible to PCs. Maybe a spell that lets you reinforce a door or wall by granting it a damage threshold + increased hit points/AC or maybe some sort of Construct race/lineage that has a trait that grants a damage threshold to the character which scales with level. 

CON limits to sprinting/dashing as derived from the chase system presented in DMG, CON ain't just hit points, it's cardio!

Another one I just thought of: Temp HP with benefits. An example is Armor of Agathys where the spell grants you temp hp, and on top of that if a creature hits you while you have those temp hp they take damage. Id love to see more variations with all the sources of temp hp out there where some give you a tagged-on boon of sorts

Quote from Kaboom979 >>

Another one I just thought of: Temp HP with benefits. An example is Armor of Agathys where the spell grants you temp hp, and on top of that if a creature hits you while you have those temp hp they take damage. Id love to see more variations with all the sources of temp hp out there where some give you a tagged-on boon of sorts

Hmm. This just gave me an idea for a wacky spell that grants temp HP, but instead of them going away when you take damage, they bounce over to someone else of your choosing as long as the spell remains up

Exhaustion has some real potential, and is currently under-used, I think. I’m liking the simpler, 10-step version in 1D&D, it seems like it will get a lot more use. Though I also like ideas people have about imposing extra conditions, like slowed, at certain points. 

It's funny, I think RAW it's the reverse, but I usually think of exhaustion in terms of the chase mechanic.  I think if D&D combats ran longer than they currently do, it'd be neat to put in some exhaustion, though I guess technically that's one of the things hit points narrate.

Occasionally I head canon D&D long movement with the premise that everyone's either Shadowfax or Aragorn/Gimli/Legolas doing the three hunters thing after Pippin and Merry.

I guess maybe the exhaustion-extended movement-chase exhaustion mechanics all play into a larger, and I'm not sure if it's a design or use neglect, exploration/survival system that deserves fuller consideration.

As a player or DM, I am fond of using encumbrance rules; my brain has a hard time justifying a character carrying anything and everything they can pick up, without any penalty. Pack animals and wagons exist for a purpose, same for magical carry devices.

I wish there was a way to make initiative more interesting without bogging it down at the same time.

In Othercide, it is really cool to be able to mess around with turn orders and delay the enemies' turns. In D&D though, it is going to be a huge hassle implementing something like that without feeling clunky and bloated. It is fine in a videogame with the computer managing the turn order for you, but I do not think something like this is easy to do in a TTRPG.

In the Digimon Card Game, you have a set amount of points you can use for actions, and once you use up all your points (or if it goes negative), it is your opponent's turn. If your points goes negative, then those negative points goes towards your opponent's points. Do you risk doing a high cost action that costs lots of points to get your board set up quickly, and let your opponent do the same immediately afterwards? The only thing I can think of to simulate something like this without feeling too clunky is to have turn-skips as a cost to do something really cool.

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I want more variety in mechanics in terms of keeping track of resources. Spell points, sorcery points, ki, etc. is basically just a regular point system. I like it, it is not bad, but I wish there was a bit more variety. I hate spell slots, it is clunky, but it is a modified point system, so I guess it is something in terms of variety. Bardic inspiration and superiority dice is basically still a point system, albeit smaller and with dice attached.

Instead of points, I like UA psionic's dice change mechanic to keep track of resources. That is really novel and fun, and I wish the main game incorporated that mechanic.

The only other thing I can think of to keep track of resources without points is to use a deck of cards, although I guess each card is a "point", but each point is unique.

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I want more spell-like options in the game. We already got normal magic spells that spellcasters can use. Battlemasters got maneuvers, which is really cool, but I think it would be good if there were even more maneuver options, and it is more easily accessible to other martials. That way, playing martials does not feel as boring and there is more room for customization, if the player so choose.

I'd like a whole subsystem for Wild Magic, with a few more mechanically impactful options. WM Sorcerer is nice and all but they and Wild Magic Barb are really the only ones that get to interact with the concept, when it should be something that can slot into a variety of settings and affect any casting class.

Tasha's has a few Wild Magic related environmental phenomena, but Wild Magic is definitely something that can be fleshed out beyond present tables.  I wouldn't mind seeing some sort of roll to learn a spell, with a potential fumble for wild magic effect.  

Quote from MidnightPlat >>

Tasha's has a few Wild Magic related environmental phenomena, but Wild Magic is definitely something that can be fleshed out beyond present tables.  I wouldn't mind seeing some sort of roll to learn a spell, with a potential fumble for wild magic effect.  

 I love those Supernatural Regions. I even tried making a "wild magic" subclass for Rangers based on them, since special terrains feel very "on theme" for Rangers

I wish more race or character abilities used Healing Surges Hit Dice as a resource and more spells and monster attacks that drained health targeted the Hit Dice pool, attacking that resource. 

Quote from AntonSirius >>

Quote from Kaboom979 >>

Another one I just thought of: Temp HP with benefits. An example is Armor of Agathys where the spell grants you temp hp, and on top of that if a creature hits you while you have those temp hp they take damage. Id love to see more variations with all the sources of temp hp out there where some give you a tagged-on boon of sorts

 

Hmm. This just gave me an idea for a wacky spell that grants temp HP, but instead of them going away when you take damage, they bounce over to someone else of your choosing as long as the spell remains up

 Or an effect of an area or trap or something, but where you're granted THP, but when someone damages you, they gain the THP. Like a game of steak the shiny from MK8D or something. It could lead to interesting tactical decisions and just be fun to play.

The mechanic that says, "no mechanic is so all-knowing and all-powerful that it cannot be ignored or changed when doing so would draw smiles from most of the table." BUT..

in the spirit of the question, I'd say, when using Darkvision to see in the dark, remember this applies:

In a lightly obscured area, such as dim light, patchy fog, or moderate foliage, creatures have disadvantage on Wisdom (Perception) checks that rely on sight. Secret doors, interacting with locks, seeing and disabling traps is not a forgone conclusion just because you play a dwarf or elven rogue.

Quote from Kaboom979 >>

Across all of the various rules and features and traits and spells and feats (and so on), there are a plethora of unique mechanics. Some are used repeatedly and show up in multiple different classes and other features, while others maybe show up once and dont get much more attention. What are some mechanics you wish were used more in game design? 

As my own examples:

1) Random Effects Tables for Bards. With the introduction of the College of Spirits Bard from Van Richten's Guide to everything, the subclass featured a unique "wild magic"-esque table of different effects which come from their "tales." What sets this table apart is that it scales with the bard's inspiration die. So the table naturally grows and gets more powerful possible effects as the bard levels up. I would love to see more Bard subclasses that use the Bardic Inspiration die in unique ways like this

2) Damage Threshold. This shows up alot for larger items and vehicles, but Id love to see some sort of Damage Threshold mechanic that is accessible to PCs. Maybe a spell that lets you reinforce a door or wall by granting it a damage threshold + increased hit points/AC or maybe some sort of Construct race/lineage that has a trait that grants a damage threshold to the character which scales with level. 

 I tend to use damage thresholds on my "minion" enemies. You can blow them apart in a single shot, but you have to deal a certain amount. I also think combining Damage Thresholds with "Boss phases" is an interesting idea (albeit, I haven't tried it before). What I mean is that the boss, once it reaches a certain amount of HP, can't have their HP reduced further until someone deals enough damage equal or more than the threshold, then the fight continues as normal. I think this is great for if you want an epic finishing blow to finish off a boss as well rather than a regular cantrip/attack

Edit: Typically my damage thresholds is defined by how much damage can be pulled off in a single turn, rather than a spell/one attack so it doesn't nerf certain classes

Quote from _Nano >>

Quote from Kaboom979 >>

Across all of the various rules and features and traits and spells and feats (and so on), there are a plethora of unique mechanics. Some are used repeatedly and show up in multiple different classes and other features, while others maybe show up once and dont get much more attention. What are some mechanics you wish were used more in game design? 

As my own examples:

1) Random Effects Tables for Bards. With the introduction of the College of Spirits Bard from Van Richten's Guide to everything, the subclass featured a unique "wild magic"-esque table of different effects which come from their "tales." What sets this table apart is that it scales with the bard's inspiration die. So the table naturally grows and gets more powerful possible effects as the bard levels up. I would love to see more Bard subclasses that use the Bardic Inspiration die in unique ways like this

2) Damage Threshold. This shows up alot for larger items and vehicles, but Id love to see some sort of Damage Threshold mechanic that is accessible to PCs. Maybe a spell that lets you reinforce a door or wall by granting it a damage threshold + increased hit points/AC or maybe some sort of Construct race/lineage that has a trait that grants a damage threshold to the character which scales with level. 

 I tend to use damage thresholds on my "minion" enemies. You can blow them apart in a single shot, but you have to deal a certain amount. I also think combining Damage Thresholds with "Boss phases" is an interesting idea (albeit, I haven't tried it before). What I mean is that the boss, once it reaches a certain amount of HP, can't have their HP reduced further until someone deals enough damage equal or more than the threshold, then the fight continues as normal. I think this is great for if you want an epic finishing blow to finish off a boss as well rather than a regular cantrip/attack

 Do you tell your players A) that you're using that rule and B) how injured the boss is?  Because otherwise it sounds like the party might be left just flailing around wondering why the boss refuses to die.  Also, that rule sounds like it favors rogues, paladins, and spellcasters.  Barbarians, fighters, and to a lesser extent rangers don't have a lot of options when it comes to boosting themselves up for big single-hit damage aside from a few subclasses.

Maybe not a mechanic per-say, but it's a shame that, of all the abilities, Intelligence doesn't seem to get as much love whereas Dexterity has become the God-Tier stat. Giving more props to Intelligence would be a nice boon but can't think of any improvement ideas off the top of my head!

Quote from Lamoon01 >>

Maybe not a mechanic per-say, but it's a shame that, of all the abilities, Intelligence doesn't seem to get as much love whereas Dexterity has become the God-Tier stat. Giving more props to Intelligence would be a nice boon but can't think of any improvement ideas off the top of my head!

 Good point.  We could go back to the 3e of extra proficiencies. Every point of int bonus could allow one more skill/language/tool proficiency. And an int minus means you get one less. 

While we’re at it, buff str as well.

I miss the Weapons vs. Armour Type modifiers from previous editions; they lent combat an element of verisimilitude, and added another dimension to gear selection, resulting in a fun and interesting increase in choices. 

Quote from Lamoon01 >>

Maybe not a mechanic per-say, but it's a shame that, of all the abilities, Intelligence doesn't seem to get as much love whereas Dexterity has become the God-Tier stat. Giving more props to Intelligence would be a nice boon but can't think of any improvement ideas off the top of my head!

 I fully agree. In my experience, you only ever get one player that does anything with Intelligence, usually the Wizard or Artificer, and they have to have proficiency in Investigation because otherwise the party suffers. If there is no Wizard or Artificer, there is just no one that takes Intelligence at all. Wisdom treads on its toes too much.