When casting a spell that the caster can cast with a spell slot, and the spell scales with the spell slot level used, then they can cast this spell with a lower level spell slot too.
When using this feature, the strain from trying to cast the spell with a too-small spell slot causes the spell to scale down at twice the rate that it scales up, and fixed damage/healing modifiers listed in the spell, as well as fixed numbers of dice, are halved for each level that the spell is scaled down, rounded down. Dice rolls can go into the negatives, and can become negative modifiers, but the total result after applying all modifiers cannot go past 0. If the spell ends up dealing a positive amount of one type of damage, and a negative amount of another type of damage, then the negative amounts counteract that amount of the other type(s).
If the scaling feature results in a 0, such as in 0 targets, 0 duration, 0 total damage, or 0 total healing, then the spell fizzles and fails to cast/continue, with the spell slot still being consumed.
Example
Disintegrate's default spell level is 6 and has a damage of 10d6+40, but forcing it through a 5th level spell slot causes its damage to change to 4d6+20, and a 4th level spell slot pushes it further to 5 minus 2d6, giving it the potential to total to 0 and fizzle.
At 3rd level and below, it becomes incredibly, if not impossibly, hard to keep it from fizzling, doing 2 minus 8d6 at 3rd, 1 minus 14d6 at 2nd, and negative 20d6 at 1st. Thus, trying to force it this low is ill-advised. 1st level spells can't be downcasted, due to the feature requiring spell slots and 0th level spell slots not existing, while 8th level spells aren't typically worded to facilitate downcasting, and 9th level spells generally don't have scaling at all.
Comments