This is for a homebrew Arcane Trickster subclass that specializes in fire damage. Although there are ways to bypass damage resistance like the Elemental Adept and Poisoner feats, there don't seem to be many ways to get past a damage immunity - other than changing the damage type using Sorcerer Metamagic / Transmuted Spell for 1 sorcery point.
Simplest option would be to state that your fire damage ignores resistance and immunity to fire - could do that if it's not too powerful, I'm just concerned that nothing else in 5e does that, it only substitutes one damage type with another.
My subclass feature substitutes the damage type for the purposes of overcoming resistance or immunity, but I'd like to know if it seems reasonable. The intention is that you pick one damage type when you hit 13th level, and that becomes a permanent substitution for damaging creatures with fire resistance/immunity - with the flavour that you're still dealing 'fire' damage, but it's intense enough to cut through.
Searing Flames
At 13th level, your flames burn hot enough to harm creatures that would normally be immune. Choose another damage type from acid, cold, lightning, poison, or thunder. For the purposes of overcoming fire resistance and fire immunity, your fireslinger spells that deal fire damage deal damage of the chosen type instead.
Another consideration is the interactions of the substituted type: a magma mephit has immunity to fire and vulnerability to cold.
So, Fire Bolt cast by a 13th level caster would do 3d10 fire damage. Target is immune to fire damage, so say you chose cold damage, Fire Bolt now deals 3d10 cold damage.
Should it trigger the mephit's cold vulnerability and deal double damage? I'm on the fence whether a way through immunity is enough of a perk already, without needing the additional benefit of triggering cold vulnerability.
Another monster to consider - an azer is immune to both fire and poison damage, so if you chose poison damage as your substitution, you're out of luck and can't hit the azer, at least not with Fire Bolt / now effectively Poison Bolt.
What about a balor - immune to fire and poison, and resistant to cold and lightning. If you chose acid or thunder, you'd deal normal damage. If you chose cold or lightning, you'd deal half damage, and if you chose poison, you're out of luck.
Should you be able to choose the substituted damage type each time? That seems too powerful/exploitable if you can gain the additional benefits of the substituted type, like vulnerability; but not too powerful if you can't get the additional benefits.
Should there be a cold to activate this feature - a spell slot, etc?
Another approach could be a straight substitution with radiant damage - might be overpowered.
Another another approach - as per the Searing Spell Metamagic from older editions: your spells that deal fire damage deal full damage to creatures with fire resistance and half damage to creatures with fire immunity.
I think a general compromise is to ignore resistance and treat immunity as resistance, rather than ignoring both.
But there's a bigger issue here. Arcane Tricksters aren't blasters. Even if they have the INT to back it up, they get spells too late to deal relevant damage with them. It's just not a role that a 1/3 caster can fill to any degree of satisfaction, and it's the reason why "fixing" the four elements monk by just decreasing ki cost still results in disappointment when you play it.
I think this archetype would be better represented by a rogue-y sorcerer or wizard subclass.
Thanks, I agree that seems the best way. I'm torn because in theory, it's not overpowered to do full damage through immunity - you could accomplish that by changing the damage type, but erring on the side of caution, I'll stick with half damage to fire immune creatures.
This is the subclass to date:
Rogue: Fireslinger
Some rogues get their hands on an alchemist’s fire and never look back. Fireslingers seek to bottle the inferno with a combination of science, magic and reckless creativity. Liable to spark chaos from a few unassuming vials, these rogues make excellent saboteurs and deadly ambushers.
3rd level: Spellcasting
Spellcasting
When you reach 3rd level, you learn how to infuse liquids and alchemical compounds with magical effects, in effect, bottling spells for later use.
Tools Required
You produce your fireslinger spell effects with vials you prepare using your alchemist’s supplies. These vials collectively serve as your spellcasting focus, and you must have one in hand to cast any spell with this Spellcasting feature. In effect, your fireslinger spells and cantrips all have an "M" component (the vial) and an "S" component (you must have one hand free to manipulate the vial), but no "V" component (you can cast spells silently).
If a cost is indicated for a component, you must have that specific component before you can prepare that spell. If a spell states that a material component is consumed by the spell, you must provide this component for each vial. Once prepared, the vials are inert, having no effect until you are ready to cast them. Provided you have access to your alchemist’s supplies, you can prepare as many vials as you need for a given day as part of a long rest.
Cantrips
You learn three cantrips: Produce Flame and two other cantrips of your choice from the fireslinger spell list. You learn another fireslinger cantrip of your choice at 10th level.
Spell Slots
The Fireslinger Spellcasting table shows how many spell slots you have to cast your fireslinger spells of 1st level and higher. To cast one of these spells, you must expend a slot of the spell's level or higher. You regain all expended spell slots when you finish a long rest.
For example, if you know the 1st-level spell Detect Magic and have a 1st-level and a 2nd-level spell slot available, you can cast Detect Magic using either slot.
Spells Known of 1st Level and Higher
You know three 1st-level fireslinger spells: Fire Bomb and two other fireslinger spells of your choice.
The Spells Known column of the Fireslinger Spellcasting table shows when you learn more fireslinger spells of 1st level or higher. Each of these spells must be of a level for which you have spell slots. For instance, when you reach 7th level in this class, you can learn one new spell of 1st or 2nd level. Learning a new fireslinger spell requires time spent brewing with your alchemist’s supplies: at least 1 minute per spell level for the new spell.
Whenever you gain a level in this class, you can replace one of the fireslinger spells you know with another spell of your choice from the fireslinger spell list. The new spell must be of a level for which you have spell slots.
Spellcasting Ability
Intelligence is your spellcasting ability for your fireslinger spells as you develop your magic through study and experimentation (often on yourself). You use your Intelligence whenever a fireslinger spell refers to your spellcasting ability. In addition, you use your Intelligence modifier when setting the saving throw DC for a fireslinger you cast and when making an attack roll with one.
Spell save DC = 8 + your proficiency bonus + your Intelligence modifier
Spell attack modifier = your proficiency bonus + your Intelligence modifier
Bombs
Bombs are the signature spells of the fireslinger, dealing explosive fire damage that scales with your Sneak Attack (see The Rogue Table). You prepare your bomb vials as you do your fireslinger spells. They are inert and non-explosive until you are ready to cast them.
3rd level: Bonus Proficiencies
Bonus Proficiencies
When you choose this archetype at 3rd level, you gain proficiency with alchemist’s supplies. Your proficiency bonus is doubled for any ability check you make that uses your alchemist’s supplies. In addition, you hone your aim to gain proficiency with thrown flasks such as alchemist’s fires and acid vials.
3rd level: Poison Resistance
Poison Resistance
Beginning at 3rd level, your experimental alchemy grants you advantage on saving throws against poison, and resistance against poison damage.
9th level: Spit Fire
Spit Fire
At 9th level, you learn how to drink the components of a bomb and expel them as a breath weapon. The breath weapon is a 15-foot cone. Each creature within the cone must make a Dexterity saving throw against your spell save DC, taking full damage as a direct hit on a failure, or half damage on a success. You must expend a spell slot of 1st level or higher to cast a bomb as a breath weapon, and once you cast a bomb this way, you cannot do so again until you have completed a short or long rest.
13th level: Searing Flames
Searing Flames
At 13th level, your flames burn hot enough to harm creatures that would normally be resistant or immune. When you deal fire damage with a fireslinger spell or cantrip, you ignore resistance to fire. In addition, you can use this feature to ignore immunity to fire a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.
17th level: Delayed Blast Bomb
Delayed Blast Bomb
At 17th level, you may choose to extend the casting time of your bombs to intensify the damage. Whenever you cast a bomb, you may choose to cast it as a concentration spell with a duration of 1 minute. When the spell ends, either because your concentration is broken or because you decide to end it, the vial explodes. If at the end of your turn, the bomb has not yet detonated, the damage increases by 1d6.
If a creature other than you touches the vial before the interval has expired, that creature must make a Dexterity saving throw. On a failed save, the spell ends immediately, causing the vial to explode and dealing damage as to that creature as though it was the target of the spell. On a successful save, the creature can throw the vial up to 20 feet. When it strikes a creature or a solid object, the spell ends, and the vial explodes.
Fireslinger Spell List
Fireslinger Spell List
Homebrew spells are marked with an * and are detailed in the New Spells section.
Cantrips
Acid Splash, Blade Ward, Control Flames, Create Bonfire, Dancing Lights, Fire Bolt, Frostbite, Mold Earth, Poison Spray, Produce Flame, Ray of Frost, Smokescreen*, Spare the Dying, True Strike
1st Level
Absorb Elements, Cure Wounds, Detect Magic, Detect Poison and Disease, Disguise Self, Expeditious Retreat, False Life, Feather Fall, Fire Bomb*, Fog Cloud, Heroism, Identify, Jump, Longstrider, Protection from Evil and Good, Purify Food and Drink, Sanctuary, Sandstone Solution*, Sleep
2nd Level
Alter Self, Barkskin, Blindness/Deafness, Blur, Continual Flame, Darkvision, Detect Thoughts, Enhance Ability, Enlarge/Reduce, Hold Person, Invisibility, Levitate, Lesser Restoration, Protection from Poison, See Invisibility, Silence, Spider Climb
3rd Level
Blink, Catnap, Clairvoyance, Feign Death, Fly, Gaseous Form, Haste, Meld Into Stone, Protection from Energy, Remove Curse, Stinking Cloud, Water Breathing, Water Walk
4th Level
Arcane Eye, Control Water, Death Ward, Elemental Bane, Fire Shield, Freedom of Movement, Greater Invisibility, Polymorph, Stoneskin, Stone Shape
You hurl a fiery vial at a creature or object within range. Make a ranged spell attack against the target. On a hit, the target takes 1d6 fire damage plus bonus damage equal to your intelligence modifier. Each other creature within 5 feet of the target must make a Dexterity saving throw against your spell save DC, taking full damage on a failed save, or half damage on a success.
The amount of damage increases as you gain levels in the Rogue class, as shown in the Sneak Attack column of The Rogue Table.
You apply a cloudy solution to a surface causing a five-foot cube of sand or dirt to become hard as stone or a five-foot cube of stone to become soft and crumbly. This effect lasts for 1 minute.
You hurl a waxy smoke pellet that sublimates on impact to create a cloud of dense smoke. Make a ranged spell attack against a target or target space. On a hit, heavy smoke fills the 5-foot space centered on the target. It lasts until the end of your next turn, or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it.
This is for a homebrew Arcane Trickster subclass that specializes in fire damage. Although there are ways to bypass damage resistance like the Elemental Adept and Poisoner feats, there don't seem to be many ways to get past a damage immunity - other than changing the damage type using Sorcerer Metamagic / Transmuted Spell for 1 sorcery point.
Simplest option would be to state that your fire damage ignores resistance and immunity to fire - could do that if it's not too powerful, I'm just concerned that nothing else in 5e does that, it only substitutes one damage type with another.
My subclass feature substitutes the damage type for the purposes of overcoming resistance or immunity, but I'd like to know if it seems reasonable. The intention is that you pick one damage type when you hit 13th level, and that becomes a permanent substitution for damaging creatures with fire resistance/immunity - with the flavour that you're still dealing 'fire' damage, but it's intense enough to cut through.
Searing Flames
At 13th level, your flames burn hot enough to harm creatures that would normally be immune. Choose another damage type from acid, cold, lightning, poison, or thunder. For the purposes of overcoming fire resistance and fire immunity, your fireslinger spells that deal fire damage deal damage of the chosen type instead.
Another consideration is the interactions of the substituted type: a magma mephit has immunity to fire and vulnerability to cold.
So, Fire Bolt cast by a 13th level caster would do 3d10 fire damage. Target is immune to fire damage, so say you chose cold damage, Fire Bolt now deals 3d10 cold damage.
Should it trigger the mephit's cold vulnerability and deal double damage? I'm on the fence whether a way through immunity is enough of a perk already, without needing the additional benefit of triggering cold vulnerability.
Another monster to consider - an azer is immune to both fire and poison damage, so if you chose poison damage as your substitution, you're out of luck and can't hit the azer, at least not with Fire Bolt / now effectively Poison Bolt.
What about a balor - immune to fire and poison, and resistant to cold and lightning. If you chose acid or thunder, you'd deal normal damage. If you chose cold or lightning, you'd deal half damage, and if you chose poison, you're out of luck.
Should you be able to choose the substituted damage type each time? That seems too powerful/exploitable if you can gain the additional benefits of the substituted type, like vulnerability; but not too powerful if you can't get the additional benefits.
Should there be a cold to activate this feature - a spell slot, etc?
Another approach could be a straight substitution with radiant damage - might be overpowered.
Another another approach - as per the Searing Spell Metamagic from older editions: your spells that deal fire damage deal full damage to creatures with fire resistance and half damage to creatures with fire immunity.
Currently homebrewing the Mistveil Rogue, an elusive infiltrator that can vanish into thin air.
I think a general compromise is to ignore resistance and treat immunity as resistance, rather than ignoring both.
But there's a bigger issue here. Arcane Tricksters aren't blasters. Even if they have the INT to back it up, they get spells too late to deal relevant damage with them. It's just not a role that a 1/3 caster can fill to any degree of satisfaction, and it's the reason why "fixing" the four elements monk by just decreasing ki cost still results in disappointment when you play it.
I think this archetype would be better represented by a rogue-y sorcerer or wizard subclass.
My homebrew subclasses (full list here)
(Artificer) Swordmage | Glasswright | (Barbarian) Path of the Savage Embrace
(Bard) College of Dance | (Fighter) Warlord | Cannoneer
(Monk) Way of the Elements | (Ranger) Blade Dancer
(Rogue) DaggerMaster | Inquisitor | (Sorcerer) Riftwalker | Spellfist
(Warlock) The Swarm
Thanks, I agree that seems the best way. I'm torn because in theory, it's not overpowered to do full damage through immunity - you could accomplish that by changing the damage type, but erring on the side of caution, I'll stick with half damage to fire immune creatures.
This is the subclass to date:
Rogue: Fireslinger
Some rogues get their hands on an alchemist’s fire and never look back. Fireslingers seek to bottle the inferno with a combination of science, magic and reckless creativity. Liable to spark chaos from a few unassuming vials, these rogues make excellent saboteurs and deadly ambushers.
3rd level: Spellcasting
Spellcasting
When you reach 3rd level, you learn how to infuse liquids and alchemical compounds with magical effects, in effect, bottling spells for later use.
Tools Required
You produce your fireslinger spell effects with vials you prepare using your alchemist’s supplies. These vials collectively serve as your spellcasting focus, and you must have one in hand to cast any spell with this Spellcasting feature. In effect, your fireslinger spells and cantrips all have an "M" component (the vial) and an "S" component (you must have one hand free to manipulate the vial), but no "V" component (you can cast spells silently).
If a cost is indicated for a component, you must have that specific component before you can prepare that spell. If a spell states that a material component is consumed by the spell, you must provide this component for each vial. Once prepared, the vials are inert, having no effect until you are ready to cast them. Provided you have access to your alchemist’s supplies, you can prepare as many vials as you need for a given day as part of a long rest.
Cantrips
You learn three cantrips: Produce Flame and two other cantrips of your choice from the fireslinger spell list. You learn another fireslinger cantrip of your choice at 10th level.
Spell Slots
The Fireslinger Spellcasting table shows how many spell slots you have to cast your fireslinger spells of 1st level and higher. To cast one of these spells, you must expend a slot of the spell's level or higher. You regain all expended spell slots when you finish a long rest.
For example, if you know the 1st-level spell Detect Magic and have a 1st-level and a 2nd-level spell slot available, you can cast Detect Magic using either slot.
Spells Known of 1st Level and Higher
You know three 1st-level fireslinger spells: Fire Bomb and two other fireslinger spells of your choice.
The Spells Known column of the Fireslinger Spellcasting table shows when you learn more fireslinger spells of 1st level or higher. Each of these spells must be of a level for which you have spell slots. For instance, when you reach 7th level in this class, you can learn one new spell of 1st or 2nd level. Learning a new fireslinger spell requires time spent brewing with your alchemist’s supplies: at least 1 minute per spell level for the new spell.
Whenever you gain a level in this class, you can replace one of the fireslinger spells you know with another spell of your choice from the fireslinger spell list. The new spell must be of a level for which you have spell slots.
Spellcasting Ability
Intelligence is your spellcasting ability for your fireslinger spells as you develop your magic through study and experimentation (often on yourself). You use your Intelligence whenever a fireslinger spell refers to your spellcasting ability. In addition, you use your Intelligence modifier when setting the saving throw DC for a fireslinger you cast and when making an attack roll with one.
Spell save DC = 8 + your proficiency bonus + your Intelligence modifier
Spell attack modifier = your proficiency bonus + your Intelligence modifier
Bombs
Bombs are the signature spells of the fireslinger, dealing explosive fire damage that scales with your Sneak Attack (see The Rogue Table). You prepare your bomb vials as you do your fireslinger spells. They are inert and non-explosive until you are ready to cast them.
3rd level: Bonus Proficiencies
Bonus Proficiencies
When you choose this archetype at 3rd level, you gain proficiency with alchemist’s supplies. Your proficiency bonus is doubled for any ability check you make that uses your alchemist’s supplies. In addition, you hone your aim to gain proficiency with thrown flasks such as alchemist’s fires and acid vials.
3rd level: Poison Resistance
Poison Resistance
Beginning at 3rd level, your experimental alchemy grants you advantage on saving throws against poison, and resistance against poison damage.
9th level: Spit Fire
Spit Fire
At 9th level, you learn how to drink the components of a bomb and expel them as a breath weapon. The breath weapon is a 15-foot cone. Each creature within the cone must make a Dexterity saving throw against your spell save DC, taking full damage as a direct hit on a failure, or half damage on a success. You must expend a spell slot of 1st level or higher to cast a bomb as a breath weapon, and once you cast a bomb this way, you cannot do so again until you have completed a short or long rest.
13th level: Searing Flames
Searing Flames
At 13th level, your flames burn hot enough to harm creatures that would normally be resistant or immune. When you deal fire damage with a fireslinger spell or cantrip, you ignore resistance to fire. In addition, you can use this feature to ignore immunity to fire a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.
17th level: Delayed Blast Bomb
Delayed Blast Bomb
At 17th level, you may choose to extend the casting time of your bombs to intensify the damage. Whenever you cast a bomb, you may choose to cast it as a concentration spell with a duration of 1 minute. When the spell ends, either because your concentration is broken or because you decide to end it, the vial explodes. If at the end of your turn, the bomb has not yet detonated, the damage increases by 1d6.
If a creature other than you touches the vial before the interval has expired, that creature must make a Dexterity saving throw. On a failed save, the spell ends immediately, causing the vial to explode and dealing damage as to that creature as though it was the target of the spell. On a successful save, the creature can throw the vial up to 20 feet. When it strikes a creature or a solid object, the spell ends, and the vial explodes.
Fireslinger Spell List
Fireslinger Spell List
Homebrew spells are marked with an * and are detailed in the New Spells section.
Cantrips
Acid Splash, Blade Ward, Control Flames, Create Bonfire, Dancing Lights, Fire Bolt, Frostbite, Mold Earth, Poison Spray, Produce Flame, Ray of Frost, Smokescreen*, Spare the Dying, True Strike
1st Level
Absorb Elements, Cure Wounds, Detect Magic, Detect Poison and Disease, Disguise Self, Expeditious Retreat, False Life, Feather Fall, Fire Bomb*, Fog Cloud, Heroism, Identify, Jump, Longstrider, Protection from Evil and Good, Purify Food and Drink, Sanctuary, Sandstone Solution*, Sleep
2nd Level
Alter Self, Barkskin, Blindness/Deafness, Blur, Continual Flame, Darkvision, Detect Thoughts, Enhance Ability, Enlarge/Reduce, Hold Person, Invisibility, Levitate, Lesser Restoration, Protection from Poison, See Invisibility, Silence, Spider Climb
3rd Level
Blink, Catnap, Clairvoyance, Feign Death, Fly, Gaseous Form, Haste, Meld Into Stone, Protection from Energy, Remove Curse, Stinking Cloud, Water Breathing, Water Walk
4th Level
Arcane Eye, Control Water, Death Ward, Elemental Bane, Fire Shield, Freedom of Movement, Greater Invisibility, Polymorph, Stoneskin, Stone Shape
New Spells
New Spells
Fire Bomb
1st-level evocation
Casting Time: 1 action
Range: 60 feet
Components: S, M
Duration: Instantaneous
You hurl a fiery vial at a creature or object within range. Make a ranged spell attack against the target. On a hit, the target takes 1d6 fire damage plus bonus damage equal to your intelligence modifier. Each other creature within 5 feet of the target must make a Dexterity saving throw against your spell save DC, taking full damage on a failed save, or half damage on a success.
The amount of damage increases as you gain levels in the Rogue class, as shown in the Sneak Attack column of The Rogue Table.
Sandstone Solution
1st-level transmutation
Casting Time: 1 action
Range: 20 feet
Components: S, M
Duration: 1 minute
You apply a cloudy solution to a surface causing a five-foot cube of sand or dirt to become hard as stone or a five-foot cube of stone to become soft and crumbly. This effect lasts for 1 minute.
Smokescreen
Conjuration cantrip
Casting Time: 1 action
Range: 60 feet
Components: S, M
Duration: 1 round
You hurl a waxy smoke pellet that sublimates on impact to create a cloud of dense smoke. Make a ranged spell attack against a target or target space. On a hit, heavy smoke fills the 5-foot space centered on the target. It lasts until the end of your next turn, or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it.
Currently homebrewing the Mistveil Rogue, an elusive infiltrator that can vanish into thin air.