Topic: Glide (Animist base spell)

[MariusH]

The Animist base list "Nature's movement/senses" has a spell called "Glide I". Does anyone have any experience with this spell? It staarts by saying that the "caster can glide like a bird", but basically it states that the product of the casters horizontal speed and his height MUST equal 100'. Never mind that the product feet/sec times feet gives a unit of square feet/sec, not feet. There are other, more pressing concerns. Like the fact that VERTICAL speed isn't mentioned at all. Can the caster choose this as he likes? It is definitely important to know.

However, most pressing is: What height should be used when calculating this product? should it be A) the height above ground where the caster cast his spell, or B) the height above ground as the caster moves along? Both has terrible problems. Let's say I am on top of a valley. In some cases I might want to glide down to the bottom of the valley, in other cases I might just want to glide right above it to the other side. Assume A) is the correct interpretation of the spell, and I want to glide down into the valley: I cast the spell, and glide away. 10' above my starting point, I have 10'/s horizontal speed. Fine. I now start descending into the valley, which lies way beyond my starting point. Approaching the level where I stood when I cast my spell (H=0'), my speed increases rapidly towards infinity. And passing through that height, to a small, but negative height, my speed suddenly changes from plus infinity to minus infinity. I guess that's gonna hurt. So now, I assume that B) is the correct interpretation, only now, I just want to glide across the valley to the other side. The valley floor is 200' beneeth my starting point. OK, so again, I glide at 10' with a horizontal speed of 10'/sec. Then I approach the valley, where the ground drops rapidly, and thus, my height above ground increases equally rapidly. My horizontal speed rapidly decreases to 0,5'/sec, since 0,5 times 200 = 100. It's almost like flying straight into a wall.

Has anyone ever used this spell, and found a SENSIBLE way to use it? I guess I could just use the "FLY" spell, but it seems like this spell should be less powerful. I guess I could just go for energy conservation, with 0,5 m*v^2 + m*g*h = constant, which would probably work well, but cause a lot of math...

[providence13]

http://www.grc.nasa.gov/WWW/k-12/airplane/glidprob.html

The spell appears to take care of some variables. You don't have to worry about thermals or weight. IMHO, the spell only does what it says. What it doesn't say is how fast you drop. It just states that height is somehow magically related to speed. The way I see it is
tan(a)= h/d. With this, you can measure off distance-time increments along the bottom of your triangle to check rate.

I would allow a Flying/Gliding Maneuver or some %Act to drop like a rock; dive. You can't dive faster than gravity allows. I do wish there was more detail in the spell description. What if magic provided a "thermal" so you could "fly like a bird"? Could you cut into duration (just an idea; 1 min/lvl is a long time for the parachute/parapont effect.) so you could remain at that height? I've seen buzzards glide around carrion for a long time, just floating in wide circles. They don't have to flap much at all if any, on a good warm day. The spell should allow you to ascend as well as descend. Glide like a kite, maybe..

But I could be way off.. 

[providence13]

http://www.csgnetwork.com/glideratiocalc.html
This could help with a bit of work..

Or http://www.exo.net/~pauld/activities/flying/PaperAirplaneScience.html

[jdale]

RMU also has this spell (as a ranger and dabbler spell) but it adds a couple sensible conditions onto the end:

7. Glide I – Caster can glide through the air. The product of caster’s altitude and horizontal speed cannot exceed 100 (with altitude in feet and speed in feet per round). For example, a caster can glide along at a rate of 5’ per round if he were 20’ off the ground, or he could glide at the rate of 50’ per round if he were 2’ off the ground. Note that the product must equal 100 (i.e., the caster cannot choose to have a result less than or more than 100). Elevation may be increased up to 5’ or decreased up to 10’ each round, with the highest elevation being used to calculate the product with the horizontal speed. There is a minimum elevation of 2’.

I think it's important to note this is not real gliding. You can increase your elevation freely (just not quickly). You don't lose altitude over time. Air currents don't affect you. Based on that, I would say the important altitude is your current distance above the ground. Not relative to the point you started over. If you fly over a valley, you can maintain a fixed speed if you also maintain a fixed distance above the ground. You can rapidly climb when going up the other side. But to maintain a fixed speed you have to follow the ground contour. If you don't follow the ground contour, so you are higher above the ground, you lose speed and quickly stall out.

I would also treat the limits on increasing/decreasing elevation as being based on your relative elevation. In one round, you can get 5' further from the ground, or 10' closer to the ground. This is true no matter how uneven the ground is.

If you want, you can think of this as ground effect hovering rather than gliding. There is a certain force that is holding you but it is linked to the ground, like a giant invisible arm.

[markc]

 I agree with JDale and the quote from RMU.
MDC

[arakish]

For a good example of this, watch the first Harry Potter movie (at least I think it was in the first one).  Watch when Lord Voldemort glides at Harry when caught drinking the unicorn's blood.

Very much like what jdale says in his post.

rmfr

[MariusH]

So when facing a cliff, of any height, I can easily glide to the top of it just by gliding towards it, since I maintain a constant speed above ground? And when gliding towards a vertical surface, I "teleport" to the top of it as I crash into it? What when the cliff actually extends outwards (so that it's possible to move beneath it's top) - how can I glide up there?

[VladD]

I'd rule you would crash in the rock and then get face scraped along the cliff at maximum speed (50' per round, or 5' per second) to the top. If it is an overhanging cliff, you get face scraped along the underside of the overhang... apply +1 per 1' of face scraping on the mechanical grinder attack table, apply criticals to the face. I think that would be sufficient to deter any cliff climbing using Glide in the future.

On a less silly note: you may climb to the cliff's edge if it is within 100 feet + character height + 2 feet (arm reach) high.
Unless you allow fractional speeds... that would get you to the moon and back with a vertical speed of 7.8 x 10^-8 feet per round.