Point is well taken, but D&D magic doesn’t take physics off the table, it violates physics within strict limits. Mundane physics still operates. As a DM a good reason I can think of for invoking physics in cases like this is that the player’s plan depends as much on physics as it does on magic, and I don’t think their cannonball trick would work. The gunpowder imparts the same momentum to the shrunken, diminished-mass cannonball as it would to a regular bullet. When the cannonball’s original size and mass are restored, it still has that much momentum - which I imagine will carry it a few feet.
Fortunately my game group includes a very smart player with a master’s degree in physics, who is very quick at computing such things. I would absolutely trust her estimate of how far the cannonball would go.
Inversing this gets really fun: enlarge spell on a tungsten/mithril bearing or toothpick. Pack enough charge to fire it out of an actual piece of siege equipment, hello nearly relativistic projectiles. Ship or battlement mounted rods from God.
"We strategically position our ship to ensure the flight path of the projectile happens in 6 second intervals, allowing for a near perfect rhythm of enlarge chanting. We keep three wizards and a wild magic sorcerer near each of our cannons.
I came here to point out exactly this: If you only shrink the ball, without reducing its size, well… you’re gonna have problems carrying the ammo.
As a DM, I think I would let them both shrink and reduce the mass, and wait till they fired the weapon before invoking “conservation of momentum” and declaring that the cannon ball drops to the ground after about a meter.
Yeah, but D&D also has spells and potions of shrink / enlarge that don’t make players start drowning in atmosphere their lungs are too small to breathe or collapse under their own weight due to square cube law restrictions, so there’s definitely some magical physics at work in there.
Well in that case, the reverse would also be true. So my barbarian can throw a cannonball at someone. How about if the mage readys the shrink spell to target the cannonball just as it leaves my hand? Conservation of energy would dictate that:
Decisions like these are what makes TTRPGs so fun, and I enjos every minute of these sort ot discussions.
Point is well taken, but D&D magic doesn’t take physics off the table, it violates physics within strict limits. Mundane physics still operates. As a DM a good reason I can think of for invoking physics in cases like this is that the player’s plan depends as much on physics as it does on magic, and I don’t think their cannonball trick would work. The gunpowder imparts the same momentum to the shrunken, diminished-mass cannonball as it would to a regular bullet. When the cannonball’s original size and mass are restored, it still has that much momentum - which I imagine will carry it a few feet.
Fortunately my game group includes a very smart player with a master’s degree in physics, who is very quick at computing such things. I would absolutely trust her estimate of how far the cannonball would go.
Inversing this gets really fun: enlarge spell on a tungsten/mithril bearing or toothpick. Pack enough charge to fire it out of an actual piece of siege equipment, hello nearly relativistic projectiles. Ship or battlement mounted rods from God.
"We strategically position our ship to ensure the flight path of the projectile happens in 6 second intervals, allowing for a near perfect rhythm of enlarge chanting. We keep three wizards and a wild magic sorcerer near each of our cannons.
We don’t lose fights often, no, why do you ask?"
Unfortunately after a single fire the force tosses the ship onto its side and is sinking
I came here to point out exactly this: If you only shrink the ball, without reducing its size, well… you’re gonna have problems carrying the ammo.
As a DM, I think I would let them both shrink and reduce the mass, and wait till they fired the weapon before invoking “conservation of momentum” and declaring that the cannon ball drops to the ground after about a meter.
Yeah, but D&D also has spells and potions of shrink / enlarge that don’t make players start drowning in atmosphere their lungs are too small to breathe or collapse under their own weight due to square cube law restrictions, so there’s definitely some magical physics at work in there.
Well in that case, the reverse would also be true. So my barbarian can throw a cannonball at someone. How about if the mage readys the shrink spell to target the cannonball just as it leaves my hand? Conservation of energy would dictate that:
Decisions like these are what makes TTRPGs so fun, and I enjos every minute of these sort ot discussions.