D&D 5E Traps for DMs to Avoid

[Werebat]

So it seems that a lot of power had been reserved for the Adam in 5E. I've seen more than one comment regarding potential trouble spots such as OP magic item combos that effectively says, "This will only come up if some DM WANTS it to."

Fair enough, but sometimes DMs don't fully realize the long term consequences of allowing or introducing certain things into their campaigns. Can anyone think of any seemingly innocuous things that a DM might be likely to mistakenly introduce into a campaign that could cause power problems down the road? Combinations of magic items and spells, etc?

 

[KarinsDad]

Well, one obvious one is the Hammer of Thunderbolts, Gauntlets of Ogre Power, and Girdle of Giant Strength.

I'm sure an Oathbow can be abused (since it is already more powerful than a +5 bow), but I don't have my DMG in front of me.

 

[transtemporal]

So it seems that a lot of power had been reserved for the Adam in 5E. I've seen more than one comment regarding potential trouble spots such as OP magic item combos that effectively says, "This will only come up if some DM WANTS it to."

Fair enough, but sometimes DMs don't fully realize the long term consequences of allowing or introducing certain things into their campaigns. Can anyone think of any seemingly innocuous things that a DM might be likely to mistakenly introduce into a campaign that could cause power problems down the road? Combinations of magic items and spells, etc?

Absolutely. Say a dm decides that +1 didnt mean much in 3e so he either adds or subtracts from the proficiency bonus. Doesnt mean much in 3e, means a heck of a lot in 5e.

Say the dm decides he doesnt like PCs killing his precious encounters, doubles monster attack and damage, or the opposite? Encounters are too hard! Halve all monster hp!

Possibilities are endless. At least spells and magic items are written down and knowable.

 

[trentonjoe]

I think magic item's with concentration spells that either: don't require concentration or concentration by a non-caster are pretty powerful. It basically removes a mechanic designed to bound that accuracy.

 

[Nergal Pendragon]

Deciding the starting points for generating a character are too few and upping it. This can unexpectedly tilt things in the favor of the PCs.

 

[Jester David]

I think the biggest problems will be house rules. DMs making rules without fully understanding the system or not really thinking through a house rule. Whether it's a change for tone or emulating a past edition or simply saying "yes" and setting an unfortunate precedent when a player asks if they can do something ridiculous.
It's easy to get rid of a magic item that's causing problems but harder for a DM to admit they were wrong and change a rule or risk alienating players by banning a once permitted action.

Really, most big DMing mistakes fall into the "system agnostic" camp. Like the DM PC, putting the players through a tightly scripted story with no choices, or having the best friend/GF/little brother player that's unkillable.

 

[Unwise]

Resurrection spells. If you want to include them in your game, do so with a lot of prior thought. If the local village has a cleric that can do it, because it will help your gaming session get on with the gaming, then you just made a potential rod for your own back. If you had a handy local that could resurrect PC#1, then it is only fair that the same apply to PC#2 later, it seems arbitrarily nasty that one town could do it and another could not. Also, how does the world work regarding resurrection, do nobles ever die? How do you assassinate people? Is anybody non-religious?

Healing injuries. In your game, do you want to have any disabled people? The old hag with arthritis, the blind begger, the old retired soldier with an arrow wound in the knee, the leper colony, the noble with a gammy leg? Players like to be able to go in to town and heal people, it makes them feel like good guys and powerful. The issue is, if everything is cure-able, you just made a world with effectively no disabled people. I don't think that is very interesting. Is it just the PCs that can do it? They will end up with nobles calling from miles around for their help, or a cult following them everywhere. If all clerics can do it, you have no disabled people.

Magic items with generic +s. If you give somebody a generic +1 sword, the only step up from there is a +2 sword. If you give them swords that have specific strengths, like demon-slaying, then you still have the ability to give them the aquatic-spear, the feybane axe, the dagger of swiftness etc. All of which will still seem cool.

PC expectations of magic items. Especially if you are coming from 4e, mercilessly crush any expectations that items in the DMG can be found in the world if the PCs seem to be relying on it. I have seen 'optimization' builds where the barbarian has low strength, because surely they will have Gauntlets of Ogre Strength by level 8. If players try that, their tears should be as honey to you.

 

[Sacrosanct]

Can anyone think of any seemingly innocuous things that a DM might be likely to mistakenly introduce into a campaign that could cause power problems down the road?

Yes. Letting a rules lawyer join the table.

 

[TarionzCousin]

Yes. Letting a rules lawyer join the table.

Hey-O!

One of the guys in my current Pathfinder game was very active in debate in high school and college. Whenever he begins a sentence with "Hypothetically speaking..." I expect (and receive) a pre-argument argument. He tries to get me to agree to something without saying what it is. Then he can follow up with "So in this instance, my character...." I never let him get away with it.

In short, know your players. Some are going to try to get away with shenanigans and some aren't. Be prepared.

 

[guachi]

Yes. Letting a rules lawyer join the table.

I see the term "rules lawyer" thrown around so much I just interpret the ad hominem to mean the person using the term has nothing to back his argument up.

Things that have come up in my game so far where I corrected the DM:

Sacred flame induces a save; it's not an attack.
No, PCs don't get a feat at character level 4; it's based on class level.
Colossus slayer can only occur once per turn, not on every attack.
Eldritch Knights can't use a focus.
Rangers can't use a focus.
Arcane Tricksters can't use a focus, either.
Yes, the dueling fighting style really does work when wielding a shield.
I take an opportunity attack when the monster leaves my reach, not when he leaves his reach. That makes no sense.
I'm an Assassin, so I really do get advantage on my first attack against any creature that hasn't gone yet.
Yes, the archery fighting style really does work with all ranged weapons - nets, darts, slings included.

In my experience, knowing the rules better than the DM = rules lawyer.

EDIT: This is in an Adventurers League game so following the rules actually matters. But even if this wasn't, springing random house rules on your players because you, as the DM, can't admit you got a rule wrong is terrible DMing.