Jabes.plays.RPG says:
Unless you just rule that the spell lets me launch stuff 90 feet regardless, in which case I would just declare max elevation every time unless there's a roof or other obstruction over our heads that prevents me from doing that. :-D
That is the restriction I was thinking; you choose the angle and elevation based on the available clearance, and the damage varies accordingly. Story-wise, a successful DEX save then might mean that the target dodged it, or (if there was a roof overhead) that you misjudged the clearance and hit the roof instead.
Naatkinson says:
If it's going to be variable damage, shouldn there be a possibility of it doing more damage than it's normal amount? Giving it a range of 1d8-3d8 makes it simply worse than things like Chromatic Orb, which don't have that variance.
It's a save rather than an attack roll, for one thing. It's a lot of discussion for this one spell, but I'm happy to consider further tweaks. Here are some possibilities I can imagine:
* Casting the spell at a higher level will either: throw a larger object (increasing damage) or throw an object farther (increasing range). Given the premise of a catapult, I feel like an additional d8 per spell slot level isn't enough for a larger object at the same velocity. Each spell level increase allows the caster to increase the weight of the object 100%. What would be preferable from a gameplay standpoint, increasing the damage by 100% - which would require multiplication: 1-3d8x(spell slot level) - or boosting the damage die, which would be more customary addition (1-3d8+6 at second level, 1-3d8+8 at third level, 1-3d8+10 at 4th level, etc)?
* Casting the spell at a higher level allows an increase to damage AND range, but it doesn't allow one to toss a larger object, it allows one to toss the same object higher/farther. 90' max for 1st level, adding 30' to the "ceiling" and range for every additional spell level. So damage is still 1d8 per vertical 30'.
* Casting the spell at a higher level only increases damage, not range, as you toss a heavier object. The spell slot level corresponds to the size of the object. Damage is normal 1-3d8 (based on elevation) + (spell slot level -1)d10. For example, tossing a heavier object 60' into the air using a 2nd-level spell slot would be 2d8+1d10, while using a 3rd-level spell slot at 90' would be 3d8+2d10.
What do you think?