How does spell hit work?

[jinath715]

It seems like my spells miss and awful lot.
Even when the hit chance is high in the high 80's and 90's. Sure, I expect them to miss sometimes, but I miss most of the time.
Meaning, out of 10 spells, I probably hit with 3-4 of those spells even when buffed.
Is the game telling me to just play melee characters?

[SnarkOne]

It's just RNGesus, even if you had two sets of 1000 spells casted, when compared you'd probably have vastly different results. Turn on the 'Weighted Dice' option & make a worthy daily sacrifice to Lolth for things to go your way.

[ShadowDark3]

When it comes to statistics, people tend to be very bad at "feeling" the proper stats. By that I mean people feel like things are happening far more or far less often than the should, when in actuality the thing is happening at the correct frequency.

Something else to consider is that with an 80% chance to hit, it would not be particularly unusual to miss 5 out of 10 attacks. It's not until you have much larger numbers (think in the 100's) that the 80% will show through (though 100 is still not a particularly big sample, and you could expect your actual number of hits to still be +/- around 12 without being considered especially lucky/unlucky).

The only way to fix this would be to de-randomize the probability of attacks (something occasionally done in competitive games with things like crit chance. League of Legends is an example). What this means is that if your chance to hit is 80%, the actual odds of you hitting are adjusted higher or lower to try and force you to have an 80% hit ratio.

As an example: Your hit chance is 50%. You attack and hit. Your current hit rate is 100%. Your next attack would have a hit chance of 25% to try and force you to have a hit rate of 50%. If you got lucky and hit a second attack in a row, your next attack would have a hit chance of 12%, because at this point you need to miss two attacks in order to get to your 50% chance to hit.

Obviously those numbers would depend on the algorithms the developer is using, but there is usually some sort of exponential scaling, so that when you are close to the target ratio, the adjustment is smaller, and as you get more or less lucky the adjustment gets larger to get you back on course. In a single player game, this kind of de-randomising is less common, as it doesn't really matter because you're not in a competitive environment.

Sorry for the wall of text, I just think this stuff is really interesting and enjoy stats and probability. Long story short, there is most likely nothing wrong with the chance to hit.

[jinath715]

Thanks for the replies.

It does seem like only certain magic spells have this issue. Such as, Sacred Flame and Eldrich Blast to name a couple. These are cantrips though so their hit chances may be totally different than any other type of spells. At least, that's how it seems from my experience.

Spells like Magic Missile always seem to hit.

Unfortunately, I don't want to ONLY use magic missile when there are tons of other spells in the game and it seems so cheap to always rely on just ONE spell to get the job done.

[Lax]

Sacred flame seems kinda weak. If you're using a cleric, or Shadowheart, I would rather use a crossbow or even go melee.

[Cyroy]

Originally posted by jinath715:

Thanks for the replies.

It does seem like only certain magic spells have this issue. Such as, Sacred Flame and Eldrich Blast to name a couple. These are cantrips though so their hit chances may be totally different than any other type of spells. At least, that's how it seems from my experience.

Spells like Magic Missile always seem to hit.

Unfortunately, I don't want to ONLY use magic missile when there are tons of other spells in the game and it seems so cheap to always rely on just ONE spell to get the job done.

Magic Missile always hits, it's part of the spell.
Besides that there are two types of spells Save spells and Attack roll spells

Save Spells: These are spells like Sacred Flame and Shatter for examples. As long as you can see your enemy you can hit people with these spells. Their hit chance is based on comparing your "save" DC against their "save" roll. Your save DC is static and increases with your spellcasting stat modifier and proficiency bonus. It is 8+SpellStat modifier+ProfBonus. Enemies check against this by rolling a d20+the save required by the spell.

Attack roll spells work a bit differently, they're like hitting someone with a bow or sword, but it is magic. Hitting someone relies on you rolling a d20+spellstat modifier+prof and checks against the enemy's AC

[WeenerTuck813]

There’s 2 ways spells hit.

Spell Attack (against their AC)
And
Spell save DC (They roll vs your DC)

Magic missiles ALWAYS HITS 100%, it’s special. We’ll, unless they use shield spell or whatever.

Here is an in depth explanation:

https://www.reddit.com/r/BaldursGate3/comments/jcghcj/guide_spells_spell_attacks_saves_and_you/

That link has all the spell info you’d need

[Lax]

Originally posted by WeenerTuck813:

There’s 2 ways spells hit.

Spell Attack (against their AC)
And
Spell save DC (They roll vs your DC)

Magic missiles ALWAYS HITS 100%, it’s special. We’ll, unless they use shield spell or whatever.

Here is an in depth explanation:

https://www.reddit.com/r/BaldursGate3/comments/jcghcj/guide_spells_spell_attacks_saves_and_you/

This is a good explanation. I have one question, though. (Speaking specifically about the example given in that write up. 8 + 2 +3 = DC 13

I understand where the +8 and the +3 Spell casting ability modifiers when making rolls. And where they are coming from.

but where is the +2 proficiency bonus coming from? Is that marked somewhere and I'm not just seeing it? Do Wizards just have a natural +2 with spells that's hidden?

[guard65]

Pretty much all the projectile class spells fall into the Ranged-Spell-Attack script for the to hit target AC. I show two AttackType.RangedSpellAttack spells and two alternate SpellRoll class spells that use ether surfaces or or a save against ability event . Not sure if Chromatic Orb is actually released yet but it is already in the code. Should give a pretty clear idea of what your dealing with

new entry "Projectile_EldritchBlast"
data "SpellType" "Projectile"
data "SpellRoll" "Attack(AttackType.RangedSpellAttack)"
data "SpellSuccess" "DealDamage(1d10,Force);"

new entry "Projectile_FireBolt"
data "SpellType" "Projectile"
data "SpellRoll" "Attack(AttackType.RangedSpellAttack)"
data "SpellSuccess" "DealDamage(1d10,Fire)"

new entry "Projectile_PoisonSpray"
data "SpellType" "Projectile"
data "SpellRoll" "not SavingThrow(Ability.Constitution, SourceSpellDC(),AdvantageOnPoisoned())"
data "SpellSuccess" "DealDamage(1d12,Poison)"
data "SpellFail" "IF(HasPassive('PotentCantrip',context.Source)):DealDamage((1d12)/2,Poison)"

new entry "Projectile_ChromaticOrb_Fire"
data "SpellType" "Projectile"
data "SpellProperties" "GROUND:SurfaceChange(Ignite);GROUND:SurfaceChange(Vaporize);GROUND:CreateSurface(2,2,Fire)"
data "SpellSuccess" "DealDamage(2d8,Fire)"

[jinath715]

Originally posted by WeenerTuck813:

There’s 2 ways spells hit.

Spell Attack (against their AC)
And
Spell save DC (They roll vs your DC)

Magic missiles ALWAYS HITS 100%, it’s special. We’ll, unless they use shield spell or whatever.

Here is an in depth explanation:

https://www.reddit.com/r/BaldursGate3/comments/jcghcj/guide_spells_spell_attacks_saves_and_you/

That link has all the spell info you’d need

Thanks!
This helps some. I see my character's AC but I have no idea what DC is or where it is on the character sheet. How do I know what my DC is?

Another thing I noticed just now was that it appears that in this game the higher the AC the better whereas in Baldurs Gate 2 it was the other way around. The lower the AC the better.

[Blackdragon]

Originally posted by jinath715:

Originally posted by WeenerTuck813:

There’s 2 ways spells hit.

Spell Attack (against their AC)
And
Spell save DC (They roll vs your DC)

Magic missiles ALWAYS HITS 100%, it’s special. We’ll, unless they use shield spell or whatever.

Here is an in depth explanation:

https://www.reddit.com/r/BaldursGate3/comments/jcghcj/guide_spells_spell_attacks_saves_and_you/

That link has all the spell info you’d need

Thanks!
This helps some. I see my character's AC but I have no idea what DC is or where it is on the character sheet. How do I know what my DC is?

Another thing I noticed just now was that it appears that in this game the higher the AC the better whereas in Baldurs Gate 2 it was the other way around. The lower the AC the better.

Again, as others said, there are ATTACK spells, when the attacker rolls against the target's ARMOR CLASS, and SAVING THROW spells, when the defender rolls against the attacker's DIFFICULTY CLASS.

In 5e, which is a dumbed down D&D edition (though not as completely moronic as 4e), both the spell attack rating and the spell's difficulty class are derived from your casting stat (INT for wizards, CHA for warlocks and sorcerers, WIS for clerics and druids). Your Proficiency bonus is added on top. The baseline is a d20 die roll for attacks, or flat 8 for difficulty class.

So this is how it's calculated:

Attack roll: 1d20 + [Proficiency Bonus] + [Spellcasting Modifier]
Difficulty class: 8 + [Proficiency Bonus] + [Spellcasting Modifier]

The result is compared to the target's Armor Class for attacks, or to the target's saving throw roll for Difficulty Class spells. Whoever has the higher number, wins.

The saving throw is calculated similar to the attack, only it's like a "defensive attack" with your DC being the "armor class".

Saving throw: 1d20 + [Saving throw Proficiency Bonus] + [Saving throw Stat Modifier]

Different classes have different Saving throw proficiencies, and the type of spell defines the stat to be used for the modifier (e.g. DEX for Fireballs, WIS for Hold Person, etc.).

Some spells have neither Attack rolls nor Saving throws, in which case the effect is simply applied without any condition to be met.

Example 1:

Bob the Wizard casts Fire Bolt against John the Fighter.

Bob's Spellcasting stat (Intelligence) is 16, which gives him a +3 modifier on the attack roll.
Bob is a 1st level Wizard, so his Proficiency bonus is +2.
Bob rolls a d20 and gets 10, making his total Attack roll = 10 +2 +3 = 15.

John has 14 Dexterity, is wearing a Chain shirt and holding a shield, which gives him an Armor Class of 13 (armor) +2 (Dex modifier) +2 (shield) = 17.

15 < 17, so Bob misses his attack and John is unscathed.

Example 2:

Enraged with his failure, Bob casts Burning Hands against John.

Burning Hands is a Saving Throw spell, with a Difficulty Class of 8 + 2 + 3 = 13.
It allows a Dexterity saving throw for half damage.

Being a Fighter, John doesn't have Proficiency in Dexterity saving throws. He rolls a 10 on his saving throw, resulting in 10 +2 (Dex modifier) = 12.

13 > 12, so John fails his Saving throw and Bob's spell does full damage against him.
Bob rolls 3d6 for damage, resulting in 3 + 4 + 4 = 11 damage.

John has 13 hit points, which leaves him at 2 hp after the attack. He is still alive and taunts Bob mercilessly.

Example 3:

Bob says "Screw it" and casts Magic Missile. This spell does not require an attack roll and does not allow a saving throw. It simply deals 3d4+3 damage to John. John is reduced to -8 hp is now a mangled pile of flesh rapidly bleeding to death.

John makes a Death saving throw: 1d20 vs. DC 10, with no modifiers applied. He rolls a 10, and manages to cling on to life for one more turn. On his turn, he uses Fighter's Second Wind to roll 1d10 +1 and heals 8 hp, putting him back at 1 hp.

Shaken by his near death experience, Bob runs away from the fight, proving once again that Wizards are superior to Fighters.

[Lax]

Originally posted by jinath715:

Originally posted by WeenerTuck813:

There’s 2 ways spells hit.

Spell Attack (against their AC)
And
Spell save DC (They roll vs your DC)

Magic missiles ALWAYS HITS 100%, it’s special. We’ll, unless they use shield spell or whatever.

Here is an in depth explanation:

https://www.reddit.com/r/BaldursGate3/comments/jcghcj/guide_spells_spell_attacks_saves_and_you/

That link has all the spell info you’d need

Thanks!
This helps some. I see my character's AC but I have no idea what DC is or where it is on the character sheet. How do I know what my DC is?

Another thing I noticed just now was that it appears that in this game the higher the AC the better whereas in Baldurs Gate 2 it was the other way around. The lower the AC the better.

Your DC is +8 as the base, +your spell attribute modifier and +2 from your classes proficiency.

for example If you have 16 INT as a wizard, your Spellcasting Modifier from attributes would be +3 Because you recieve a +1 every 2 attribute points.

10 INT: 0
12 INT +1
14 INT +2
16 INT +3 and so on.

So in this example your total DC would be 13. 8+2+3 = 13

+8 as the base.
+2 from proficiency.
+3 from attributes.

If i'm wrong please correct me. This is how I understand it.

[Blackdragon]

In general, it's really silly how this game does not show spell DCs on tooltips. It also doesn't show the rolls themselves, despite it being a feature of D&D-based CRPGs for decades. As a result, people not intimately familiar with D&D mechanics are left in the dark about its most basic elements.

[Lax]

Originally posted by Blackdragon:

In general, it's really silly how this game does not show spell DCs on tooltips. It also doesn't show the rolls themselves, despite it being a feature of D&D-based CRPGs for decades. As a result, people not intimately familiar with D&D mechanics are left in the dark about its most basic elements.

As a newbie to DnD i'm inclined to agree with you. I'm learning as I go... or At least trying to lol

My guess is the devs are trying to simplify things to not overwhelm novices to DnD that just want to play the game.

[Blackdragon]

Originally posted by Lax:

Originally posted by Blackdragon:

In general, it's really silly how this game does not show spell DCs on tooltips. It also doesn't show the rolls themselves, despite it being a feature of D&D-based CRPGs for decades. As a result, people not intimately familiar with D&D mechanics are left in the dark about its most basic elements.

As a newbie to DnD i'm inclined to agree with you. I'm learning as I go... or At least trying to lol

This actually reminds me of how I played BG1 for the first time back in the 1990's, without a manual or any knowledge of AD&D. Took me a while to figure out how THAC0 worked.

Originally posted by Lax:

My guess is the devs are trying to simplify things to not overwhelm novices to DnD that just want to play the game.

Dumbing down a game's interface in order "not to overwhelm" is very unflattering to the players and eventually counterproductive, because not having access to hard data about how the game works creates the exact confusion they were trying to avoid.

Unless they are literally aiming at the console/mobile audience, and/or purposefully lowering the bar to not make people care about mechanics, thinking that mindlessly mashing buttons and watching colorful animations = fun gameplay.

[Lax]

Originally posted by Blackdragon:

Originally posted by Lax:

As a newbie to DnD i'm inclined to agree with you. I'm learning as I go... or At least trying to lol

This actually reminds me of how I played BG1 for the first time back in the 1990's, without a manual or any knowledge of AD&D. Took me a while to figure out how THAC0 worked.

Originally posted by Lax:

My guess is the devs are trying to simplify things to not overwhelm novices to DnD that just want to play the game.

Dumbing down a game's interface in order "not to overwhelm" is very unflattering to the players and eventually counterproductive, because not having access to hard data about how the game works creates the exact confusion they were trying to avoid.

Unless they are literally aiming at the console/mobile audience, and/or purposefully lowering the bar to not make people care about mechanics, thinking that mindlessly mashing buttons and watching colorful animations = fun gameplay.

True. Preferably, I would like have more information in terms of mechanics than less. Especially if i'm trying to learn something new.