# D&D calculations compilation

Published by Deer Lord in the blog Deer Lord's blog. Views: 187

A bunch of quick ones I did:

1. Call lightning
Spoiler:

http://engl393-dnd5th.wikia.com/wiki/Call_Lightning

Meaning the spell can either give you control over a natural storm, or make a storm cloud for you.
Either way the spell can rain down cloud to ground lightning, that are dodge-able.

What's interesting is that if you choose to spawn a cloud it appears 100 ft, or 30m above ground.
If we are having an average 1.7m tall character attempting to dodge it, they'd have to move 1.5m (5 ft.) to get out of the way before the lightning clears 28.3m of distance.

Average lightning speed = 97,536 m/s
t=d/v= 28.3/97536 = 2.9015e(-4) sec
v=d/t= 1.5/2.9015e(-4) = 5169.75 m/s, or Mach 15.2

This also doubles as a dc feat since lightnings are naturally building level in dc.

2. Disintegrate
Spoiler:

http://engl393-dnd5th.wikia.com/wiki/Disintegrate

The spell can reduce a 10 foot cube of any ordinary material to dust.
This includes the likes of steel and glass

Pulverization of steel = 310-1000 J/cc
Pulverization of Glass = 1000 J/cc

V= 10 ft^3 = 283168.466 cc
E= 283168.466*1000= 283168466 J, or 0.067 tons of TNT
Small-building level.

3. Proctiv’s Move Mountain (Epic Spell in Forgotten Realms)
Spoiler:

- Player's Guide to Faerun (3.5e)

Pretty specific.
From what we know this spell was used to make flying cities, that went pretty high (considering they were destroyed almost completely when they fell and could traverse mountainous territory)
So as a conservative estimate I'll show strong you need to be to lift one up a kilometer.

Volume of said mountain is 4289320000 m^3
density of granite rock = 2700 kg/m^3
m=4289320000*2700= 11581164000000 kg

Pe= m*g*h= 11581164000000*9.8*1000 = 113495407200000000 J
or, 27.126 Megatons of TNT, City-level

4. The Avatar of Gilgeam throws a dragon turtle
Spoiler:

- Powers and Pantheons

According to the Monster Manual, Dragon turtles weight between 8000 to 32000 pounds, so using these as a low and high end.
8000 pounds = 3628.72 kg , 32000 pounds = 14514.88 kg
afaik OBD considers a City to be at least 10km in diameter, so I'll use that.

From the Ballistic trajectory calculator I can find the height it went up to and make a graph.
with an angle of 45 degrees and fiddling with speed until I get that 10km mark

nets us a speed of 313.2 m/s

Low end: Ke=0.5*m*v^2= 0.5*3628.72*(313.2)^2 = 177978265.2864 J, or 0.042 tons of TNT
High-end: Ke=0.5*m*v^2= 0.5*14514.88*(313.2)^2 = 711913061.1456 J, or 0.17 tons of TNT
Small-building level, eh

Final Tally:
Dodging Call lightning = Mach 15.2
Disintegrate dc = 0.067 tons of TNT
The avatar of Gilgeam throws a dragon turtle= 0.042~0.17 tons of TNT
Netherese Archwizards create flying cities= 27.126 Megatons of TNT
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