D&D 5E Rules We Have Been Doing Wrong This Whole Time

[Li Shenron]

Five editions in, it is easy to accidentally think you know how a rule works. For example, I just found out via another thread that I have been doing saving throws wrong this whole time: a natural 20 does not automatically save in 5E. Huh.

What were you getting wrong because you made an assumption, didn't read closely and/or applied an old rule accidentally?

At the beginning I didn't have the DMG. I was using passive checks as described in the PHB i.e. very loosely based on my own choices. Then I read the DMG and found that it has more precise rules about using passive perception when searching for hidden things.

Was I playing wrong?

No. Because the DMG isn't even officially "required" to play the game. And because the official WotC stance is that DM's stuff is always meant to be a toolset for a DM to interpret and adopt as they see fit.

If a 20 doesn't succeed, why was anyone even rolling?

If the DM notices that a 20 won't succeed, they in fact don't need to ask for a roll, why assuming they were rolling?

Sometimes however the DM might still want to make players roll just because he doesn't want them to know that they cannot succeed. If they then roll a 20, the DM can tell them they did so good that they figured out they can't succeed even with the best effort.

And of course sometimes the DM just doesn't notice they can't succeed until they roll a 20, but that's another matter.

Neither of those are how you do it, not that it matters (you can do it however you like).

Group checks, though, would be that whatever the dc happens to be, if half the party makes the dc, then they make the group check. If more than half the party fails, then the group check is failed.

You don't have to use group checks for stealth, though, unless you want to. (It's usually only worth doing as a group check for a "general" stealth check (such as across a fairly large area) not for more specific us-vs-them.

(I'm tired, I don't know if I made that make any sense.)

I think you make very sense. The whole group check section keeps using the term "might" when talking about the DM using group checks. It's pretty much the key of DM rules being tools and not laws. You can use group check and you can not use group checks, and be right either way.

 

[Charlaquin]

I learned not too long ago that I've been doing group Stealth checks "wrong" for years.

How I've been doing it: everyone makes a Stealth check, and I take the lowest result. The assumption being that the group is only as stealthy as its least-stealthy member.

How the rules say to do it: everyone makes a Stealth check and I'm supposed to take the average (I think?) or something like that. The assumption being that monks and rogues can exude so much stealth that it suppresses the noise and sheen of nearby suits of armor. Somehow.

Anyway, I like my way better.

By the book, the group passes a group check if at least half of the group would pass the check. Which is… kind of similar to the average? It’s like the average of the group’s binary pass/fail results, instead of the average of their check totals.

Anyway, the only thing the PHB says about when to use a group check is “When a number of individuals are trying to accomplish something as a group, the DM might ask for a group ability check,” and the one example given is of navigating through a swamp. So, I don’t actually think it’s clear that a group check is “supposed to” be used when the party is sneaking.

 

[UngeheuerLich]

Yeah, and the reasons for not allowing you to delay seem....dubious. So instead, you're forced to figure out a trigger for a reaction that might let you do something later in the turn as opposed to right now.

After playing for a while now, I realized that the delay action mainly caused delays in play and made Dex way more powerful.
I wonder how many people who argue that dex is too strong because it gives a bonus to initiative allow the delay action as a house rule.

 

[UngeheuerLich]

I learned not too long ago that I've been doing group Stealth checks "wrong" for years.

How I've been doing it: everyone makes a Stealth check, and I take the lowest result. The assumption being that the group is only as stealthy as its least-stealthy member.

How the rules say to do it: everyone makes a Stealth check and I'm supposed to take the average (I think?) or something like that. The assumption being that monks and rogues can exude so much stealth that it suppresses the noise and sheen of nearby suits of armor. Somehow.

Anyway, I like my way better.

I guess, for stealth vs passive percetion it is the average... not the arithmetic average but the median (taking the higher value if it is split between two values).

For surprise however you use the lowest.

 

[Weiley31]

The ever popular "Thank goodness Darkvision is there in this scary dark cave. Sorry Bill the Human" that everybody and their mother does/handwaves.

All the 5E games I've played/been in have handwaved Encumbrance and all that. So "default" Powerful Build just sits there looking pretty most of the time on whichever race has it. (Although, now that the Giff of Adventures in Space has an updated version of Powerful Build now (Hippo Strength as it was called in the Spelljammer UA), that probably won't be an issue anymore.

Stealth would've been another issue, but I just do a "Stealth Roll vs Passive Perception, adjust appropriately depending on if Advantage/Disadvantage is in effect" and just find that to be a lot simpler. Now, whether or not I should be doing that kind of roll every couple of times compared to Stealth Person rolls a stealth check once before the mission and just let that be bygones is a whole nother matter entirely and may still play into the nature of the thread's question.

 

[James Gasik]

I don't handwave Darkvision. I apply it's penalties, and it's really devalued the ability.

 

[UngeheuerLich]

I am running Dungeon of the Mad Mage, which is mostly unlit and the secret doors are all DC 20 to detect.

One of the players, who is playing a dwarf cleric/paladin and has a high Perception, took the Dungeon Delver feat thinking the +5 from advantage to his passive Perception would let him auto-detect all the secret doors … until I pointed out that since the party all has darkvision and doesn’t use any light, the disadvantage to Perception from the dim light would negate the advantage from the feat. So if he wants to be able to auto-detect all the secret doors, he’s going to need to start using a light source.

Yes. Here comes the big advantage of dancing light over light.
You can have them dance around and before you leaving yourself in darkness but still seeing perfectly with darkvision (as they only shed dim light).

My rogue made great use of them combined with darkvision.
I'd also say, if you do darkvision right, concentration is absolutely warranted, as it is practically invisibility for you.

 

[Horwath]

we do the rules wrong intentionally, or as you would call it house rules;

initiative is rolled after surprise round,
delay is back in,

 

[Horwath]

I don't handwave Darkvision. I apply it's penalties, and it's really devalued the ability.

darkvision penalty is applied to everything sight based, except attack rolls for us,

that includes perception, investigation, tool usage, insight, survival for tracking,

 

[Reynard]

You can have them dance around and before you leaving yourself in darkness but still seeing perfectly with darkvision (as they only shed dim light).

Darkvision does not say, according to the SRD, anything about seeing better in dim light.

"Within a specified range, a creature with darkvision can see in darkness as if the darkness were dim light, so areas of darkness are only lightly obscured as far as that creature is concerned. However, the creature can’t discern color in darkness, only shades of gray"