D&D 4E Changing saving throws to 4e style DC's - can someone walk me through an example?

[Herobizkit]

My brain is tired and I can't grok the math atm. I want to encourage players to "roll all the dice" and have them target ability scores/saving throw DC's rather than roll saves for every enemy they encounter.

Is it feasible with the 'bounded accuracy' mechanic in play?

 

[pedr]

Players make all the rolls is one of the variants in an Unearthed Arcana article: http://dnd.wizards.com/articles/features/variant-rules

You could just use the saving throw part, and leave monsters rolling to hit an AC with physical attacks, I'm sure.

 

[pukunui]

4e's defenses were just the "take 10" version of saving throws. So to do that in 5e, let the players just add 10 to all their saving throw modifiers and you're done! You could also re-add Fortitude, Reflex and Will easily enough, too, by letting the players add their choice of either Str/Con, Dex/Int, or Wis/Cha mods respectively.

 

[Sage Genesis]

Players make all the rolls is one of the variants in an Unearthed Arcana article: http://dnd.wizards.com/articles/features/variant-rules

You could just use the saving throw part, and leave monsters rolling to hit an AC with physical attacks, I'm sure.

Important Notice: the math in the UA article is wrong.

Quick example.
A level 1 caster with a 16 casting stat has a save DC of (8+2+3) 13.
Let's say there's a critter with a +2 save bonus, so it's a perfect 50-50 chance whether it saves or not.

Under the UA version, the caster would have a +5 bonus and would roll against DC 13. He can do that on a roll of 8, and all of a sudden the monster's chances of "saving" successfully is only 35%.

In order for the system to work properly with the same odds as before the DC needs to be (14+save bonus) instead of (11+save bonus).

 

[CapnZapp]

Yes, ignore the ua article.

Trying to use its system will make your brain hurt much more than figuring it option your own...

 

[CapnZapp]

4e's defenses were just the "take 10" version of saving throws. So to do that in 5e, let the players just add 10 to all their saving throw modifiers and you're done! You could also re-add Fortitude, Reflex and Will easily enough, too, by letting the players add their choice of either Str/Con, Dex/Int, or Wis/Cha mods respectively.

This, otoh, is some useful advice well suited to weary brains!

 

[Dausuul]

4e's defenses were just the "take 10" version of saving throws. So to do that in 5e, let the players just add 10 to all their saving throw modifiers and you're done!

11, actually, if you want to keep everything functionally the same.

• Replace each save bonus with an "ability defense" of 11 plus the bonus. For example, a goblin with a Dex save of +3 has a Dex defense of 14.
• Replace each save DC with a "power bonus" of the DC minus 11. For example, a PC wizard with a fireball save DC of 16 would have a power bonus of +5.
• Instead of a saving throw, make a power check against the ability defense. So instead of the goblin making a Dex save at +3 against DC 16, the wizard makes a power check at +5 against the goblin's Dex defense of 14.

This has the effect of keeping probabilities the same. In the traditional system, the goblin needs a 13 or better to make the save. That's a 40% chance to save and a 60% chance to fail. In the new system, the wizard needs a 9 or better to make the check, which is a 60% chance to "hit" and a 40% chance to "miss."

Either way, there's a 60% chance the goblin takes full fireball damage and a 40% chance it takes half.

 

[Rune]

And don't forget that (dis)advantage adds +/- 5 to a static DC, so, if an NPC has (dis)advantage on a save, it's saving throw "roll" is effectively 6 or 16 + ability and/or proficiency modifiers, instead of 11 (+). This actually opens up the possibility that the attacker can also have (dis)advantage, which is not normally possible. If you want to avoid this, don't add the (dis)advantage modifier to the DC at all. Instead, apply the inverse of the save's (dis)advantage to the attacker's roll.

 

[Tony Vargas]

The inversion is screwy because save DCs are 8 + mod + prof, not 10+

So:

Important Notice: the math in the UA article is wrong.

Quick example.
A level 1 caster with a 16 casting stat has a save DC of (8+2+3) 13.
Let's say there's a critter with a +2 save bonus, so it's a perfect 50-50 chance whether it saves or not.

Under the UA version, the caster would have a +5 bonus and would roll against DC 13. He can do that on a roll of 8, and all of a sudden the monster's chances of "saving" successfully is only 35%.

In order for the system to work properly with the same odds as before the DC needs to be (14+save bonus) instead of (11+save bonus).

Why so high? Well, there's three things going on here.

1) Save DCs start at 8, not the 3e-traditional 10, which was really 10+ spell level, because...

2) 10 doesn't give you a 'fair save,' either, it's 11 that would give a 50/50 save all-things-being-equal, because,

3) When you invert a DC you have to take into account that who wins on a 'tie' switches

So, yes, rolling d20 + stat (+prof, maybe) vs 8 + caster stat + prof inverts to rolling d20 + caster stat + prof vs 14 + stat + (prof, maybe).

If that sounds hard, that's because, yes, it's hard (at first). A lot of targets, tough, are going to have non proficient saves and a low stat, meaning you just hit the base 14, or maybe even 13 or 12. And, while the caster always gets proficiency, the target often won't, especially if the caster can figure out it's worst save.

And don't forget that (dis)advantage adds +/- 5 to a static DC, so, if an NPC has (dis)advantage on a save, it's saving throw "roll" is effectively 6 or 16 + ability and/or proficiency modifiers, instead of 11 (+). This actually opens up the possibility that the attacker can also have (dis)advantage, which is not normally possible. If you want to avoid this, don't add the (dis)advantage modifier to the DC at all. Instead, apply the inverse of the save's (dis)advantage to the attacker's roll.

That last bit, yes: One advantage of the attacker always rolling, is that there's no inverted language around adv/dis. Instead of "attackers have advantage against you and you have disadvantage on saves," you just have "you grant attackers Advantage."

 

[MechaPilot]

My brain is tired and I can't grok the math atm. I want to encourage players to "roll all the dice" and have them target ability scores/saving throw DC's rather than roll saves for every enemy they encounter.

Is it feasible with the 'bounded accuracy' mechanic in play?

I've had success with just replacing the monster's save with its ability score. For example, if a monster would normally make a Strength save, the PC's roll with bonuses must beat the monster's Strength score. It's certainly not perfectly spot on. But it works very well for a fast and dirty system.

I also use a monster's ability score for contested rolls too, just to cut down on the amount of rolling.