D&D 5E How would imposing no stacking of magic affect 5E game balance?

[GX.Sigma]

It wouldn't affect balance much--Clerics would quickly learn that bless is useless beyond a certain point, and PCs would make sure to spread around magic items.

It would certainly be counter-intuitive and complicated.

So the real question is, why would you want to do this?

 

[Jester David]

It comes up. All. The. Time. Bless is a big culprit. It + paladin aura, all the time. Any magic weapon in the party + Bless, all the time. Haste + any magical defense, all the time. Sacred weapon + Bless + magical weapon, all the time.

"All. The. Time." being for groups that have a cleric and/or paladin in the party for bless. And a sorcerer or wizard for haste. So, really, half the time. Maybe even less.

 

[Umbran]

Because the boosted strength is a magical effect - put the character in an anti-magic field and it goes away. If a Barbarian had 26 Str (possible with the appropriate Tome or Libram) then that would count as natural, because it wouldn't go away in an AMF.

Yes, I know it is a magical effect.

My question is - how does the sword know that?

With the magic weapon, there's some indescribable field of magic about it that makes it hit better. It isn't just that it is sharper or something distinct and physical (or else you couldn't have, say, a magic mace or club with no edge). And the Guidance spell creates a similar effect. And we can imagine that these fields don't add together. That makes sense, in the game world.

But, that belt doesn't make some indescribable magic field. It actually makes the character stronger, something distinct and physical. It is hard to see why that indescribable field has a problem with the distinct and physical effect. I mean, if you had a spell that made a character taller, would you say their sword couldn't reach up into a tree to hit someone, because the magic of being taller couldn't interact with the +3? Why is "being magically taller" okay, but "having magically mightier thews" is not?

Moreover, consider: You have a +3 on your sword. You have a +2 on your shield. The sword affects the sword. The shield affects the shield. And you are fine. But the sword affects the sword, and the belt affects your muscles! Why doesn't this work?

Your answer is effectively that it doesn't work because the sword and belt both impact the same *die roll*. But the magic happens in the game world, the die roll does not! Magic doesn't actually know about die rolls! The impact on the die roll is merely an abstraction of the impact of magic in the game world, and is thus a poor justification for how magic works in the game world.

Other editions have handled this by saying that magical bonuses *of the same type* didn't stack, and went to the length of making up this huge list of bonus types. This put things in a logical framework that made sense, but was a pain in the neck and a source of mi-maxing. We probably don't have to do that far. We only have to go so far as to answer the question, "Does it make sense *in the game world*?"

So, answer me - *in the game world*, why can't the magic strength and magic sword stack?

 

[Umbran]

"All. The. Time." being for groups that have a cleric and/or paladin in the party for bless. And a sorcerer or wizard for haste. So, really, half the time. Maybe even less.

I'm guessing "cleric and wizard in the party" is probably more than half the parties out there.

 

[Umbran]

So, answer me - *in the game world*, why can't the magic strength and magic sword stack?

Oh, and I should bring this back to the original question - what would this do to game balance?

Well, how crafty are your players? If you give them the "two magics on the same thing do not stack" situation, they are *going* to start asking why, say, the Aid spell (which magically grants hit points) and a lightning bolt (which magically takes away hit points) should stack, and so on. Players are *very* clever. They will pester and abuse you, if they feel you are being a tad too arbitrary about it. And they have more brains than the GM does. They *will* find cases that do things you don't like.

Which is to say, don't screw with them too much, and balance will be fine

 

[Tony Vargas]

So, answer me - *in the game world*, why can't the magic strength and magic sword stack?

Questions like that can always be answered, thanks to magic being so arbitrary and ill-defined. Maybe the item's bonus comes because it strikes faster & harder than a normal weapon, because it's 'alive in your hand, fighting with you?' Perhaps superhuman strength like that granted by the belt, overwhelms that added speed and power?

Maybe they're auras are incompatible? They set up contrary etheric vibrations? They will stack, but only when the Doomstar is in the 7th House and the periwinkle wanderer in retrograde (be patient, it'll happen in 20000 years)?

Giving the Belt of Giant Strength and +3 sword to two different characters because they don't stack is also less annoying than the DM sending a Disenchanter to eat one or the other.

 

[Umbran]

Questions like that can always be answered, thanks to magic being so arbitrary and ill-defined.

Yeah, but as I noted above, answering that in a satisfactory way, that doesn't lead to unintended consequences, is somewhat more difficult.

The problem is with answers that amount to, "because I don't want you to have nice things," are not going to be appreciated by the players. And that will have unintended consequences.

 

[SteveC]

Off the top of my head, I'd say:
It would make characters fail at slightly more checks.
It would flatten out modifiers more, so you would have the D20 with more influence.
It would make some actions at the top of the difficulty scale become impossible.
It would make magic items less interesting: once you have +1 armor, the only thing that can improve on it is +2 armor.
It would make the buffing role of spellcasting less desirable.

Like some of the other posters, I'd ask what you're really trying to accomplish: are characters hitting too often in combat or making too many skill checks? From what I've seen, characters who work together to be the best they can at challenges is a good thing, but I also haven't seen the game become trivialized either.

So what's the goal you want to accomplish?

 

[Tony Vargas]

Yeah, but as I noted above, answering that in a satisfactory way, that doesn't lead to unintended consequences, is somewhat more difficult.

Magic doesn't have to be all that consistent.

The problem is with answers that amount to, "because I don't want you to have nice things," are not going to be appreciated by the players.

D&D seems to assume it works for fighters. ;P Besides, if the DM didn't want them to have nice things, he wouldn't have given them two whole magic items in the first place.

 

[aramis erak]

Subject really asks it all, but just to elaborate, suppose no magic spells or effects stack on the d20 roll at all? If you have a +3 sword and Guidance in effect, they don't stack (so you better roll a 4). If you have +1 armour and +1 shield, they don't stack. If you have a +3 sword and a Belt of Giant Strength, they don't stack.

Not going to break the game. It will have some effects...

It will limit the ability to overcome tougher monsters to higher level characters.
It will increase the value of attributes.
It will increase the value of proficiency bonus increases.
It will decrease the value of a mixture of boosting spells.