D&D 5E What are some Rules misunderstandings that turned into houserules in your game?

[Stalker0]

Every DM misunderstands the rules from time to time, and so starts playing the game a certain way. Sometimes once you realize your mistake, you correct it...but other times you like the "mistake" and decide to keep it. What are some of yours?

For me I have a couple:

• Grapple and Trip are allowed on a Opportunity Attack. So technically it requires an attack action to swap out attacks for things like grapple and trip, which I didn't realize at first. But I found that it was the start of getting my players to use those mechanics more often, and now they really enjoy trying to grapple the bad guy as he runs away sort of thing...so I kept it.
• You can reduce falling damage by half the result of an Acrobatics check. To this day I still don't know where I got this idea from, but for a long while I thought it was in the core book. Once I realized the mistake....I like having this nice core use for Acrobatics and my players seem to enjoy it, so I kept it in.

 

[Voadam]

You can reduce falling damage by half the result of an Acrobatics check. To this day I still don't know where I got this idea from, but for a long while I thought it was in the core book. Once I realized the mistake....I like having this nice core use for Acrobatics and my players seem to enjoy it, so I kept it in.

In the 4e PH, page 181:
"Reduce Falling Damage (Trained Only) If you fall or jump down from a height, you can make an Acrobatics check to reduce the amount of falling damage you take.
Reduce Falling Damage: Free action if you fall or a move action if you jump down.
✦ Damage Reduced: Make an Acrobatics check, and reduce the amount of falling damage you take by one-half your check result (round down)."

 

[Stalker0]

In the 4e PH, page 181:
"Reduce Falling Damage (Trained Only) If you fall or jump down from a height, you can make an Acrobatics check to reduce the amount of falling damage you take.
Reduce Falling Damage: Free action if you fall or a move action if you jump down.
✦ Damage Reduced: Make an Acrobatics check, and reduce the amount of falling damage you take by one-half your check result (round down)."

Aha! So more an old rule than a house rule.

 

[Blue Orange]

There's some evidence linear falling damage in D&D was originally supposed to be quadratic (as makes more sense from the physics point of view) but this was misinterpreted and the rule stuck.

 

[Sithlord]

There's some evidence linear falling damage in D&D was originally supposed to be quadratic (as makes more sense from the physics point of view) but this was misinterpreted and the rule stuck.

Glad the misinterpretation stuck

 

[Voadam]

There's some evidence linear falling damage in D&D was originally supposed to be quadratic (as makes more sense from the physics point of view) but this was misinterpreted and the rule stuck.

I implemented that as a house rule a lot.

It goes well with my real life fear of heights and how in Voadam's brain projection fantasy world falling is very scary.

It also means you don't need a 50 foot deep pit to do the damage of an OD&D-3.5 minimum caster level fireball.

Most falls in D&D usually come down to 10 to 20 feet anyway or are in the ridiculously high up category.

 

[CubicsRube]

Every DM misunderstands the rules from time to time, and so starts playing the game a certain way. Sometimes once you realize your mistake, you correct it...but other times you like the "mistake" and decide to keep it. What are some of yours?

For me I have a couple:

• Grapple and Trip are allowed on a Opportunity Attack. So technically it requires an attack action to swap out attacks for things like grapple and trip, which I didn't realize at first. But I found that it was the start of getting my players to use those mechanics more often, and now they really enjoy trying to grapple the bad guy as he runs away sort of thing...so I kept it.
• You can reduce falling damage by half the result of an Acrobatics check. To this day I still don't know where I got this idea from, but for a long while I thought it was in the core book. Once I realized the mistake....I like having this nice core use for Acrobatics and my players seem to enjoy it, so I kept it in.

I actually wanted to add grapple and trip as opportunity attacks.

How does it work for you? Any memorable moments?

 

[Stormonu]

• Grapple and Trip are allowed on a Opportunity Attack. So technically it requires an attack action to swap out attacks for things like grapple and trip, which I didn't realize at first. But I found that it was the start of getting my players to use those mechanics more often, and now they really enjoy trying to grapple the bad guy as he runs away sort of thing...so I kept it.

Apparently, I've been using this "house rule" since day one.

 

[Stalker0]

I actually wanted to add grapple and trip as opportunity attacks.

How does it work for you? Any memorable moments?

Tons. Just last night we had a big one.

So when the big villain was revealed (this was a one shot game), he threw down the corpse of his nemesis, one of the previous heroes from the last one shot I ran.

During the fight (which was in a high up clock tower), one of the party members turned the body into a ghoul. Well I couldn't have it be just any ghoul (as it was a former player character), so it was the undead form of the hero back to action!

The main villain was tossed into a cloudkill, and the ghoul leaped after him. Just as the villain was moving to get out, the ghoul managed to grapple him (using the house rule), pulling him back in the cloud. A round later, as the villain had gotten further beat up, a big hole in the wall had opened up. The villain was about to throw down, so the Hero Ghoul pulled him cinematically up to his face, shouted out "I'll meet you in hell!" and hurled them both through the hole and off the ledge (using the half move rule of grappling). Hero and Villain died together, with rip roaring applause!

 

[Horwath]

It's more of a old rune than misunderstanding:

We roll initiative after 1st round(surprise round),