Would a Shrink Item on a balista bolt work in a cross bow and would it still do 3d8dmg?

[LucasB]

My mage wants to shrink Balista bolts and use them in his Cross bow.
Now I know it won't work because a command word is a standard action.
But there is this

can be returned to normal composition and size merely by tossing them onto any solid surface I assume that impacting a plate mail does not constitute a solid surface or flesh for that fact.

How would you guys literate this?

I would assume that the 3d8 Dmg is based on the shear kinetic mass force behind the bolt...

That's like saying a throw a rock at someone and expand it into a cannon ball does it keep going with the same kinetic force as the little rock? No because its mass just increased 1/4,000 times sure would work great if you had no gravity or any resistance then sure but we are not in space.

[Theconiel]

Suppose a ballista bolt is 4' long. A ballista bolt subjected to a Shrink Item spell is then a cloth-like object 3" long. How ya gonna shoot that?

Plus, your wizard better make damn sure the bolt isn't in his pack or quiver when the spell's duration expires.

EDIT: The cloth-like state is optional. I missed that.
OK, so the wizard could tie the ballista bolt to a crossbow bolt to shoot it.

But what happens when the bolt suddenly expands? Using a perfectly inelastic collision as a guide, I suggest that the bolt suddenly changes in weight from 0.1 lb (CRB Crossbow bolt) to 24 lb (my guess). Its momentum is conserved, so it slows down. A lot.
I would say that the damage does not change.

[My Self]

Get a slightly oversize ballista bolt.

It doesn't turn cloth-like unless you specifically want it to.

If you want to be an inefficient Vital Striker with 1/2 BAB, go ahead.

[UnArcaneElection]

The spell you really need is Gravity Bow.

[Theconiel]

UnArcaneElection wrote:

The spell you really need is Gravity Bow.

...or Fireball

[Byakko]

Couple problems with this idea:

Shrunken balista bolts are still balista bolts. They won't work in a crossbow. (they would work in a shrunken balista, though...) Now, I'd probably allow it in a cinematic moment, but from a rules perspective they're not the same type of ammunition so I wouldn't allow it as part of a character's shtick.

"tossing on a solid surface" probably entails you doing exactly that. Whether this would trigger if you merely "dropped" it is questionable, but shooting it, on the other hand, is distinctly different than tossing it.

Finally, I'd advise against bringing physics into any discussion involving size change. You'll wind up with massive explosions as mass is converted to energy, people getting jettisoned off the planet, and things like that. Just assume the magic takes care of it. ;)

[Captain Phoenix]

Go with whatever is going to be the most fun. The bolts work, just like crossbow bolts. If they're in the target when the spell wears off, 3d8 damage baby (Maybe a 25% chance of impaling a target)! If the spell wears off before then, I'd say they're much less accurate.

[The Wyrm Ouroboros]

Ah, we used to do this, back in the day. We wound up coming up with a spell that would do specifically this - shrink ballista bolts specifically crossbow-bolt-sized objects which, when fired from a crossbow (because a ballista is basically an oversized crossbow, right?), would automatically transform back into ballista bolts without changing the speed/heading/etc. Which basically let you do ballista damage with the crossbow.

The crossbow had to be the same 'type' as the ballista, however - but this was back when there were light ballistae and heavy ballistae - so a bolt slung by a light crossbow did damage as a light ballista, heavy crossbow equalled heavy ballista. (If you want to port over the idea, call the current ballista a light ballista; for heavy, increase damage by a die, critical range is the same, cost to 750gp, and increment to 150'. Penalties are the same for firing, though reloading requires three full-round actions - though of course, if you have a crew larger than 1, you can split that up amongst the crew. Takes up space 5' across but 10' long.)

The real issue is that of time; if you exceed your 1 day / level, your quiver of crossbow/ballista quarrels is gonna cause some real problems ...