D&D 5E No cover rules, just dis/adv, what breaks?

[Juriel]

So, we started playing with Starter Set + Basic rules, and the interaction of concealment and cover is just ugly, with this being the one place where you have modifiers all of a sudden.

What issues arise if we just ignore cover rules completely, and just give dis/advantage as appropriate? Instead of +5 to Reflex saves versus that fireball from being in a barrel, you get Advantage on the save, etc.

 

[Juriel]

Okay, firing into melee, you cannot assume the other participants give minor cover (+2 to AC), and instead you'd take the Disadvantage hit or nothing...

Seeing how Disadvantage is -3 on average, that might be close enough? Would just hit archer Rogues bad.

But wait, do the rules even say that firing into melee gives a penalty?

 

[wedgeski]

It seems they really, really want to differentiate between some, a lot, and total cover. +5 being the equivalent of Advantage is Implied by the rules elsewhere, so that works fine for three-quarters cover.

 

[KarinsDad]

Seeing how Disadvantage is -3 on average, that might be close enough? Would just hit archer Rogues bad.

Disadvantage is closer to -5 on average.

 

[jadrax]

So, we started playing with Starter Set + Basic rules, and the interaction of concealment and cover is just ugly, with this being the one place where you have modifiers all of a sudden.

What issues arise if we just ignore cover rules completely, and just give dis/advantage as appropriate? Instead of +5 to Reflex saves versus that fireball from being in a barrel, you get Advantage on the save, etc.

• You don't get any benefit from cover against attacks at long range.
• You lose the distinction between Half Cover and Three-quarters Cover.

Personally, I like it the way it is, but it's hard to see that changing it to Disadvantage is going to break the game.

 

[Juriel]

Disadvantage is closer to -5 on average.

The average die result difference IS closer to 3. But, the effect it has on outcome for the most common rolls is COMPARABLE to 4 or 5...

So yes, it could be much worse than expected.

 

[KarinsDad]

So, we started playing with Starter Set + Basic rules, and the interaction of concealment and cover is just ugly, with this being the one place where you have modifiers all of a sudden.

I wouldn't call it ugly. We've all played having 0 to 5 various competing bonuses and penalties on a given situation for years. Is it really terrible to have a single +2 or +5 in the rules somewhere?

What issues arise if we just ignore cover rules completely, and just give dis/advantage as appropriate? Instead of +5 to Reflex saves versus that fireball from being in a barrel, you get Advantage on the save, etc.

With advantage being +5, there isn't a good way to differentiate between 1/2 cover and full cover without at least one of them being a modifier.

You could probably get away with replacing 3/4 cover with disadvantage on the AC attack, or advantage on the Dex save, but doing this for half cover will seriously impact your game.

Advantage (being +5) is a seriously heavy modifier and should rarely be given to the PCs unless the rules call out for it. Although rolling 2D20 is fun, it's a bit of a wonky solution with regard to probabilities and should be used sparingly (unless the core rules actually call for it).

 

[Juriel]

I wouldn't call it ugly. We've all played having 0 to 5 various competing bonuses and penalties on a given situation for years. Is it really terrible to have a single +2 or +5 in the rules somewhere?

It comes up as this weird ONE thing that is done differently.

You could probably get away with replacing 3/4 cover with disadvantage on the AC attack, or advantage on the Dex save, but doing this for half cover will seriously impact your game.

Ah, good point. Viewing it as an effective -5 penalty (on rolls where you just needed 11 to hit, say, since it takes you from 50% success down to 25% success rate), does make half cover huge.

Hmm.

 

[KarinsDad]

Okay, if we're nitpicking...

The average die result difference is closer to 3.

Though, the effect it has on outcome for the most common rolls (you're just aiming to roll somewhere between 7 to 14) is COMPARABLE to 4 or 5.

Ok, if we're nitpicking...

It's rarely close to even 4.

For the 10 number range where probably 99% of rolls need to be made:

Number needed on D20, Normal chance to hit, Advantage chance to hit, equivalent bonus

15 30% 51.00% 4.2
14 35% 57.75% 4.55
13 40% 64.00% 4.8
12 45% 69.75% 4.95
11 50% 75.00% 5
10 55% 79.75% 4.95
09 60% 84.00% 4.8
08 65% 87.75% 4.55
07 70% 91.00% 4.2
06 75% 93.75% 3.75

This works out to an average 4.575 bonus to the die roll for this range of 10 numbers. Plus the chance of needing an 11 (+5 equivalent) in any given situation occurs more frequently than needing a 6. So, this ups the overall average closer to about +4.8 or higher.

For things like attacking where there is a critical, advantage nearly doubles the crit range. From a DPR perspective, a PC with advantage does about 50% more damage than a PC without advantage. This equates to about +1.2 more to hit. The overall bonus to damage is equivalent of getting +6 to hit on the die roll.

So, it is closer to +5 (or +6) and is rarely +4 and never +3.

 

[Juriel]

Ah, there's the math! I couldn't find it right now, thanks.

That's lot bigger shift than expected, sheesh.