I was trying to cast banishment and after me and DM and others at table read how it works there was some confusion. FYI assume I am pretty noob. I don't understand saves and rolls very well yet.
TL;DR -- need to understand save rolls for this and outcomes:
You attempt to send one creature that you can see within range to another plane of existence. The target must succeed on a Charisma saving throw or be banished.
If the target is native to the plane of existence you’re on, you banish the target to a harmless demiplane. While there, the target is incapacitated. The target remains there until the spell ends, at which point the target reappears in the space it left or in the nearest unoccupied space if that space is occupied. If the target is native to a different plane of existence than the one you’re on, the target is banished with a faint popping noise, returning to its home plane. If the spell ends before 1 minute has passed, the target reappears in the space it left or in the nearest unoccupied space if that space is occupied. Otherwise, the target doesn’t return.
At Higher Levels: When you cast this spell using a spell slot of 5th level or higher, you can target one additional creature for each slot level above 4th.
so first confusion was that DM said that the spell has to be "against something" so he did it against my spell DC - I don't understand how this works, would you not roll a D20 - compare to the the charisma level+ modifier of the creature? on a tie the effect fails? We were fighting a star spawn I think, but it seems there are many types, I am not sure what one - they did mention that they had really high dex, but low charisma (after other spells were stonewalled with dex saves).
If the charisma was 16 (+3) that is 19 -- so banishment would only work on a roll of 20? You would add modifier right?
Lets assume a the effect works - in that case we have 2 cases --- the question is what defines "when the spells ends" what does this mean, does it mean, after 1 min, or I lose concentration?
Case 1 - creature is of current plane
Then creature sent to demi plane, incapacited, and returns to same place, or nearest place after "?? the spells ends??"(what does this mean) ... do they return incapacitated?
Case 2 - creature is of another plane
Then creature sent to their "home" plane, -- after 1 min they are stuck there, but if concentration is lost, they return.
The creature you're trying to banish roll a saving throw vs yourSpell save DC (= 8 + your proficiency bonus + your ability modifier). Your spell save DC should stand in the description of the spell if you have the character on Dndbeyond.
It's a charisma saving throw, so it's D20+charisma modifier + an eventual bonus (like proficiency bonus).
If you are a wizard, and your spell save DC is 15 and try to banish a creature. The creature roll D20 and add its charisma saving throw modifier. If the roll is equal to the DC (15) or higher, the creature succeeds and is NOT banished.
Case 2 - Yes.
Case 1 - The creature is incapacitated WHILE it is banished, not when it returns (as I read the description). The spell ends after a minute or if you loose concentration before that.
The way this is resolved is like any other resisted spell: the target makes a save (unless otherwise noted, a Charisma check) against your save DC. If it fails, it is affected. If your save DC is 16, and its charisma bonus is +3, it rolls d20+3 against a DC of 16, so a raw roll of 12 or less (meaning an adjusted roll of 15 or less) fails.
A spell ends when its duration expires, you stop concentrating on it, or some other effect ends it (e.g. dispel magic).
The target is only incapacitated while they are in the demiplane.
You attempt to send one creature that you can see within range to another plane of existence. The target must succeed on a Charisma saving throw or be banished.
The creature that you're trying to target must make a Charisma saving throw. If their save is equal to or higher than your spell save DC, nothing happens. Otherwise, they suffer the effects of the spell.
If the target is native to the plane of existence you're on, you banish the target to a harmless demiplane. While there, the target is incapacitated. The target remains there until the spell ends, at which point the target reappears in the space it left or in the nearest unoccupied space if that space is occupied.
Creatures native to the current plane are sent to a demiplane. "While there, the target is incapacitated." The target is not incapacitated once it returns. The reappear in the exact spot, or as close to it, as physically possible (i.e they won't reappear inside an object if you banish a creature and then push a boulder into the place where it was).
To make a saving throw, you roll the d20 and add the relevant ability modifier (e.g for a Charisma saving throw, add your Charisma modifier, which would be +3 if you have a Charisma of 16) and potentially your proficiency bonus (if you have proficiency in that saving throw). For spells you cast, the save DC (the number to match or beat to avoid the effects) is always your spell DC.
"You attempt to send one creature that you can see within range to another plane of existence. The target must succeed on a Charisma saving throw or be banished."
When you cast a spell that forces a creature to make a saving throw to resist the effect, the value they have to meet or exceed with the roll is the caster's Spell Save DC. That is equal to 8 + the caster's proficiency bonus + the ability modifier for the ability used to cast the spell(usually the same ability for all spells they cast and determined by their class, but for multiclassed characters or characters of races that have their own innate spellcasting, this sometimes gets complicated). When a monster has to make a save, it's the d20 roll plus the appropriate ability modifier unless the monster's stat block lists a specific bonus for that save(go look at the save bonuses for ancient dragons, and weep).
If you're unfamiliar with the concept of saving throws and Spell Save DC, Chapter 7 of the PHB, "Using Ability Scores" covers Saving Throws, and Chapter 10 "Spellcasting" covers things like your Spell Save DC, Spell Attack Bonus, etc. I know the Players Handbook covers a lot of material, but it's laid out really well and is easy to follow.
"If the target is native to the plane of existence you're on, you banish the target to a harmless demiplane. While there, the target is incapacitated. The target remains there until the spell ends, at which point the target reappears in the space it left or in the nearest unoccupied space if that space is occupied."
So if you banish something native to where you are when you banish them, they get shunted off to a temporary Time Out place, and can't do anything while they're there. When the spell ends, either by the duration running out or you dropping/losing Concentration, they pop right back where they were. Great way to take a boss baddie out of a fight for a while so you can clear out the minions first.
"If the target is native to a different plane of existence than the one you're on, the target is banished with a faint popping noise, returning to its home plane. If the spell ends before 1 minute has passed, the target reappears in the space it left or in the nearest unoccupied space if that space is occupied. Otherwise, the target doesn't return."
THIS is where Banishment gets reeeeeeally fun. If the target is from another plane, they go back home while the spell is running. They only get to come back when the spell ends early, if it runs the full minute, they don't pop back. Now, this doesn't prevent them from coming back of their own accord by some other means. Let's say there's a senior Devil servant of an Arch-Devil who's been sent to the Material plane to carry out the Arch-Devil's agenda. As a symbol of his rank he's been given an amulet that lets him Plane Shift once a day, only between the Material Plane and the Arch-Devil's home base in the Nine Hells. If you cast Banishment on the devil and he fails the save, he's banished back to it's native plane in the Nine Hells(not necessarily to his boss' HQ, mind you). If the spell drops early, the devil pops back. If you can keep the spell going the full minute, the devil is still in Hell after it ends. If he hasn't used his amulet yet today, he can still use it to come back, however.
"At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, you can target one additional creature for each slot level above 4th."
It's a 4th-level spell, so you need to use a spell slot of 4th level OR HIGHER to cast it. Some spells have altered effects when cast at higher levels. Sometimes it means more dice in the damage roll(see: Fireball), sometimes it increases the duration(see: Hex). For spells like Banishment, Invisibility, Hold Person, etc. it means additional targets. Each target has to make their own saving throw to resist the spell, and each target is banished to whichever location is appropriate for its home plane. But you only maintain Concentration for the spell as a whole. If your Concentration drops before the spell's natural duration, every target pops back.
I'm going to try to shorten the answers as much as possible.
For banishment, the target makes a CHA save against your spell save DC.
Your spell save DC is 8+proficiency bonus+spellcasting ability modifier. (If you are a level 7 cleric with 18 WIS, that us 8+3+4=15).
For the target to make a save, it rolls a d20 plus its save modifier listed in its stat block, or just its ability modifier is none is listed (For a star spawn hulk that is d20-1). If the result is equal ot higher than your save DC, it passed the save.
A spell ends at the end of its duration, if you stop concentrating on it, or it is forcibly ended.
When banishment ends and the creature returns, it is no longer incapacitated.
If the creature is banished to its home plane for a full minute without losing concentration, it stays there.
I was trying to cast banishment and after me and DM and others at table read how it works there was some confusion. FYI assume I am pretty noob. I don't understand saves and rolls very well yet.
TL;DR -- need to understand save rolls for this and outcomes:
Spell says : https://roll20.net/compendium/dnd5e/Banishment#content
so first confusion was that DM said that the spell has to be "against something" so he did it against my spell DC - I don't understand how this works, would you not roll a D20 - compare to the the charisma level+ modifier of the creature? on a tie the effect fails? We were fighting a star spawn I think, but it seems there are many types, I am not sure what one - they did mention that they had really high dex, but low charisma (after other spells were stonewalled with dex saves).
If the charisma was 16 (+3) that is 19 -- so banishment would only work on a roll of 20? You would add modifier right?
Lets assume a the effect works - in that case we have 2 cases --- the question is what defines "when the spells ends" what does this mean, does it mean, after 1 min, or I lose concentration?
Case 1 - creature is of current plane
Then creature sent to demi plane, incapacited, and returns to same place, or nearest place after "?? the spells ends??"(what does this mean) ... do they return incapacitated?
Case 2 - creature is of another plane
Then creature sent to their "home" plane, -- after 1 min they are stuck there, but if concentration is lost, they return.
The creature you're trying to banish roll a saving throw vs your Spell save DC (= 8 + your proficiency bonus + your ability modifier). Your spell save DC should stand in the description of the spell if you have the character on Dndbeyond.
It's a charisma saving throw, so it's D20+charisma modifier + an eventual bonus (like proficiency bonus).
If you are a wizard, and your spell save DC is 15 and try to banish a creature. The creature roll D20 and add its charisma saving throw modifier. If the roll is equal to the DC (15) or higher, the creature succeeds and is NOT banished.
Case 2 - Yes.
Case 1 - The creature is incapacitated WHILE it is banished, not when it returns (as I read the description). The spell ends after a minute or if you loose concentration before that.
Ludo ergo sum!
The way this is resolved is like any other resisted spell: the target makes a save (unless otherwise noted, a Charisma check) against your save DC. If it fails, it is affected. If your save DC is 16, and its charisma bonus is +3, it rolls d20+3 against a DC of 16, so a raw roll of 12 or less (meaning an adjusted roll of 15 or less) fails.
A spell ends when its duration expires, you stop concentrating on it, or some other effect ends it (e.g. dispel magic).
The target is only incapacitated while they are in the demiplane.
The creature that you're trying to target must make a Charisma saving throw. If their save is equal to or higher than your spell save DC, nothing happens. Otherwise, they suffer the effects of the spell.
Creatures native to the current plane are sent to a demiplane. "While there, the target is incapacitated." The target is not incapacitated once it returns. The reappear in the exact spot, or as close to it, as physically possible (i.e they won't reappear inside an object if you banish a creature and then push a boulder into the place where it was).
To make a saving throw, you roll the d20 and add the relevant ability modifier (e.g for a Charisma saving throw, add your Charisma modifier, which would be +3 if you have a Charisma of 16) and potentially your proficiency bonus (if you have proficiency in that saving throw). For spells you cast, the save DC (the number to match or beat to avoid the effects) is always your spell DC.
"You attempt to send one creature that you can see within range to another plane of existence. The target must succeed on a Charisma saving throw or be banished."
When you cast a spell that forces a creature to make a saving throw to resist the effect, the value they have to meet or exceed with the roll is the caster's Spell Save DC. That is equal to 8 + the caster's proficiency bonus + the ability modifier for the ability used to cast the spell(usually the same ability for all spells they cast and determined by their class, but for multiclassed characters or characters of races that have their own innate spellcasting, this sometimes gets complicated). When a monster has to make a save, it's the d20 roll plus the appropriate ability modifier unless the monster's stat block lists a specific bonus for that save(go look at the save bonuses for ancient dragons, and weep).
If you're unfamiliar with the concept of saving throws and Spell Save DC, Chapter 7 of the PHB, "Using Ability Scores" covers Saving Throws, and Chapter 10 "Spellcasting" covers things like your Spell Save DC, Spell Attack Bonus, etc. I know the Players Handbook covers a lot of material, but it's laid out really well and is easy to follow.
"If the target is native to the plane of existence you're on, you banish the target to a harmless demiplane. While there, the target is incapacitated. The target remains there until the spell ends, at which point the target reappears in the space it left or in the nearest unoccupied space if that space is occupied."
So if you banish something native to where you are when you banish them, they get shunted off to a temporary Time Out place, and can't do anything while they're there. When the spell ends, either by the duration running out or you dropping/losing Concentration, they pop right back where they were. Great way to take a boss baddie out of a fight for a while so you can clear out the minions first.
"If the target is native to a different plane of existence than the one you're on, the target is banished with a faint popping noise, returning to its home plane. If the spell ends before 1 minute has passed, the target reappears in the space it left or in the nearest unoccupied space if that space is occupied. Otherwise, the target doesn't return."
THIS is where Banishment gets reeeeeeally fun. If the target is from another plane, they go back home while the spell is running. They only get to come back when the spell ends early, if it runs the full minute, they don't pop back. Now, this doesn't prevent them from coming back of their own accord by some other means. Let's say there's a senior Devil servant of an Arch-Devil who's been sent to the Material plane to carry out the Arch-Devil's agenda. As a symbol of his rank he's been given an amulet that lets him Plane Shift once a day, only between the Material Plane and the Arch-Devil's home base in the Nine Hells. If you cast Banishment on the devil and he fails the save, he's banished back to it's native plane in the Nine Hells(not necessarily to his boss' HQ, mind you). If the spell drops early, the devil pops back. If you can keep the spell going the full minute, the devil is still in Hell after it ends. If he hasn't used his amulet yet today, he can still use it to come back, however.
"At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, you can target one additional creature for each slot level above 4th."
It's a 4th-level spell, so you need to use a spell slot of 4th level OR HIGHER to cast it. Some spells have altered effects when cast at higher levels. Sometimes it means more dice in the damage roll(see: Fireball), sometimes it increases the duration(see: Hex). For spells like Banishment, Invisibility, Hold Person, etc. it means additional targets. Each target has to make their own saving throw to resist the spell, and each target is banished to whichever location is appropriate for its home plane. But you only maintain Concentration for the spell as a whole. If your Concentration drops before the spell's natural duration, every target pops back.
I'm going to try to shorten the answers as much as possible.