Acid Splash 2e FAQ FAQ
Does Acid Splash use grenade-like missile rules in AD&D 2e?
No. The D&D Portal 2e conversion borrows the idea of minor acid splash damage from AD&D 2e grenade-like acid rules, but the spell does not use the grenade-like missile subsystem itself. You do not make a thrown-object attack roll, calculate grenade range bands, roll for scatter, or determine where a missed flask lands. Acid Splash uses its own spell range and saving throws vs. spell.
AD&D 2e has detailed rules for thrown acid and other grenade-like missiles, including direct hits, splash damage, misses, and scatter. Those rules are useful design inspiration for a spell named Acid Splash. Using the entire subsystem for a small 1st-level Wizard spell would make the conversion much slower and more complicated than its damage justifies, so D&D Portal keeps only the thematic idea of a minor splash.
Acid Splash has its own spell resolution
The caster chooses one creature within the spell's 30-yard range. The target then makes a saving throw 
D&D Portal - Saving Throw D20 test rule Saving Throw is a d20 test rule used to resolve
uncertain outcomes during play. Full link: https://dnd-portal.com/rules/d20-tests/saving-throw/ vs. spell.
There is no missile attack roll and therefore no normal attack miss that needs to be converted into a scatter result.
Nearby creatures within 3 feet also make saves against the secondary splash. Those saves are part of the spell rather than consequences of a physical flask landing somewhere.
The 1-point splash is the main design inspiration
AD&D 2e grenade-like Acid 
D&D Portal - Acid Damage type Acid is a damage type used by attacks,
spells, class features, resistance, immunity, and vulnerability. Full link: https://dnd-portal.com/rules/damage-types/acid/ rules establish the idea that a direct Acid D&D Portal - Acid Damage type Acid is a damage type used by attacks,
spells, class features, resistance, immunity, and vulnerability. Full link: https://dnd-portal.com/rules/damage-types/acid/ hit can be accompanied by much smaller damage to nearby creatures.
The Portal conversion echoes that pattern by giving the primary creature 1d4 potential damage and nearby creatures only 1 point.
That resemblance is intentional, but it does not mean the spell is mechanically treated as a thrown Acid D&D Portal - Acid Damage type Acid is a damage type used by attacks,
spells, class features, resistance, immunity, and vulnerability. Full link: https://dnd-portal.com/rules/damage-types/acid/ flask.
The spell does not use scatter or grenade range bands
Physical grenade-like missiles can involve short, medium, and long ranges, attack modifiers, and rules for determining where a missed throw lands.
None of those steps apply to Acid D&D Portal - Acid Damage type Acid is a damage type used by attacks,
spells, class features, resistance, immunity, and vulnerability. Full link: https://dnd-portal.com/rules/damage-types/acid/ Splash. Its range is always the spell's listed 30 yards, and its success is determined by saving throw D&D Portal - Saving Throw D20 test rule Saving Throw is a d20 test rule used to resolve
uncertain outcomes during play. Full link: https://dnd-portal.com/rules/d20-tests/saving-throw/ rather than weapon-attack accuracy.
The spell also has no bottle to break and no physical projectile that remains on the battlefield after a miss.
Why the distinction matters at the table
Treating Acid D&D Portal - Acid Damage type Acid is a damage type used by attacks,
spells, class features, resistance, immunity, and vulnerability. Full link: https://dnd-portal.com/rules/damage-types/acid/ Splash as a grenade-like missile would add several rolls and special cases to a spell whose primary damage is only 1d4.
It could also create unintended interactions with weapon proficiencies, missile modifiers, physical ammunition, and item rules that the conversion was not designed to use.
Keeping the systems separate makes the spell fast to resolve while still giving it an AD&D-flavored splash effect.