Saturday Spell-Part Water

PartWaterThe moonless night was good cover, but the orcs had patrols and check points on the roads. They’d need a different way onto the peninsula for this mission to be a success. Dirinshild knew a water walking spell, but getting this group across would require too many spells. Maybe one or two gnomes, but this strike force needed a new approach.

He knew what to do. He cast a while. When he finished, the water parted, the way was clear.

This spell uses the water speed mechanic present in Water Walking and the Diver’s Helm to create outward pushing currents. As with water walking, the speed is converted to a pressure countering the tendency of the water flow back into place.

Right Hand:

Neta (Nature Radius): Water (Full), Order (Full)

Vi (Water Arc): Water (Half), Order (Half)

Vi (Water Arc): Water (Full), Order (Full)

Vi (Water Arc): Water (Half), Order (Half)

Vi (Water Arc): Water (Full), Order (Full)

Vi (Water Arc): Water (Half), Order (Half)

Vi (Water Arc): Water (Full), Order (Full)

Vi (Water Arc): Water (Half), Order (Half)

Vi (Water Arc): Water (Full), Order (Full)

Neta (Nature Radius): Water (Half), Order (Half)

saying “on re loa”

How well this performs depends largely on how deep the water is and what kind of distance we want out of it. Let’s talk power first. I’m using it as a persistent effect spell, so far used mostly for battlefield control. That means we start with 2*(18d6+10d3+5)*10/2 mph of water flow and declines linearly over 10d6+10d3+5 minutes. This averages 880 mph of water flow to start, reducing linearly over 60 minutes. Keep in mind that as we approach the end of the period, the passage will have shrunk to far to be passable.

Now a look at the math. I’m going to take the pressure equation from water walking and set it against the equation for pressure from a dam. As a GM I have to make a call limiting the cross-sectional origin area of this 880 mph current to stop the spell being infinitely powerful, so I’m going to limit the origin area to 12 square feet, the vertical area directly in front of a large person. Alright, that gives us a water force of 12*0.5*62.4*(880*1.467)^2 pounds. That goes up against 62.4*32*Depth/2*(2*Length*Depth). For a passage that is narrow relative to the total width of the body of water, the depth is not changed appreciably from the natural depth of the body of water.

Now, let’s say the water is 20 feet deep on average and we’re crossing where it is 600 feet wide. From this we can determine how long this will last before we find ourselves wading, on average. This gives us a necessary speed of 770 mph, so we’d only have 7.5 minutes to cross, on average, before our feet start getting wet, though an argument could be made for the shallow parts staying dry longer. Increasing depth reduces the time significantly, while increasing length has less of an effect.

This spell is expensive at 312 SP, and it takes 15-20 seconds to cast, but that sounds worth it to me. For longer or deeper passages, it just takes more power. This spell is widely scalable.

This could work crossing a river,  but the math becomes more complicated as the river backs up and adds more and more force. It wouldn’t be too bad, but expect the spell to last less time.

Would get water components in order to cast a spell like this? Would you like to have a spell like this available in the party? Any other spells or variations you’d like to see? Tell us below and we may do it in a coming week.

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