Magic Mapping?

I'm doing some brainstorming for a magic item I'd like to make. Basically no restrictions, I'm just trying to figure out what effects you'd need and rough levels.

What I want is before enchantment, a piece of leather big enough to use as a map, but completely blank. After enchantment, it should accurately copy all terrain around it onto the map. It either needs to have a fixed map scale, or be able to resize as necessary (so if you start mapping, then go on a month-long sailing trip, it should shrink the map each time you reach the edge of the leather so the whole map still fits). The user should be able to erase the map when they're done, and add comments for things magic wouldn't detect (like names of cities). The map needs to be readable until you erase it, and you should be able to make a nonmagical, permanent copy of the map without using Vis.

Effect 1: "See terrain". Sense the exact location and elevation of the terrain around the map. InTe 20 (base 2 "visible property", R: Per, D: Con, T: Vision, 1 uses per day, device maintains concentration.) You would add Aq and Her requisites and 1 magnitude if you wanted waterways & forests drawn on the map instead of just contours. Can be once a day since you usually won't be travelling nonstop for 24 hours, and concentration lets you "turn it off" when you are done mapping and don't want the map to change anymore. I suppose if you started with InVim, you might be able to add regios or auras to the map, but that would add a magnitude or two since the base effect would be level 3, and possibly another magnitude or two for more accurate regio shape detection.

2: "Draw map". Draw lines and areas by changing the color of the map leather. MuAn 15 (Base 1 "color change", R: Per, D: Sun, T: Part, 2 uses per day, sunrise/sunset trigger, +1 magnitude for carefully & accurately drawn lines, 2 linked triggers - one to the "see terrain", one to the "mentail control") I thought this would work better than controlling or creating ink since this way the map can easily change, be erased & reused, etc. This effect would also be used to erase the map and make annotations when combined with mental control. One thing I'm not sure of is if continuous effect would let the map change as it got updates, or if continuous just means "the colors change when this effect triggers, and are continually the same after".

3: "Mental control". The effect described in the main book under linked trigger, an InMe 30 effect. The user can give commands to erase the map, add notes to points on the map, zoom in and out to a limited extent.

4: "Copy map". When commanded, while touching ink and a writeable surface, create a permanent copy of whatever the map currently shows. ReAq 7 (Base 1 "gentle control", R: Touch, D: Mom, Tar: Ind, +2 mags for very unnatural control, 1 use per day, linked to the "mental control" effect)

Requires a total of 8 pawns to enchant these effects, so needs to be either a piece of leather the size of a shield, or a slighly smaller leather with bone edging.

So does this do what I want it to do? And any suggestions on improving it?

Effect 1: the map does not see, so it cannot use a vision target. Besides, if it did it would be limited to Vision range, which in a forest is not very much. I recommend you make that a Touch range, Part target, and put your remaining magnitudes into +Sizes. If you can afford +5 Size, you can have it affect a circular area 1 foot deep and about 1,000 paces in radius, that's a one kilometer radius map. Add one magnitude and you could learn two properties: contour and 'what's on top', which would give you rivers and forests without an additional requirement.

Alternatively you could use an Intelligo Auram effect, Base 4, 'sense air and its boundaries' (See the Eyes of the Bat spell). Range Touch, Target Part. The standard size of an individual of Auram is 100 paces across, so what you lose from the higher base you win back from having to use fewer magnitudes.

Effect 2: interesting idea changing the material itself, should work

Effect 3: no problem

Effect 4: I'm not sure, but you might require an extra magnitude or two to control ink, it being a more unnatural liquid than water. Only Creo Aquam specifically mention it though, and I'm not even sure if ink counts as an unnatural liquid. Also, you had better measure your ink carefully beforehand, because you spell will use it all whether you want to or not :slight_smile:

That's why you give it a magical sense to see. That's what Sense Target effects do. They give the recipiant a magical sense.

Like Richard said, Target vision should give it a magical sense, which is why it is range personal. Just like Eyes of the Bat (range personal, target hearing). And for a travelling magus, things to extend your sight are easy (levitate, climb a ladder, travel by boat or road, etc). I also figure the user would be interested in either where the edge of the forest is, or specific points in the forest, both being pretty easy to identify with sight. Then you just fill in the whole area inside the boundary with green ink and say "here there be forest spirits" :slight_smile:

Auram could definitely identify the contours, but looking at EotB I'm not sure "sonar" would give you enough detail to identify what's on top - shape yes, but not to tell tree from column, road from river (auram wouldn't be able to "look" below the surface of the water), wall from waterfall. Maybe 1 extra magnitude to improve that. Although, if you were going into caves and wanted to map beyond the reach of your light source, hm...

Yeah, ink seemed like a bad idea since that might mean enchanting the ink, you would definitely have to provide enough ink, there's the question of erasing and reuse (you're spending all this vis, so it better not be single-use). Imaginem would probably work instead, but I'm not as comfortable designing Im spells, and there's this nice MuAn guideline already in the book. And since parchment is (approximately) leather is animal product...

Look under Muto Aquam. Slightly unnatural is things like water with funny colors, make a nasty liquid taste good, etc... I suppose ink of hermes might be weird enough to qualify, but not regular ink. And the Rego guidelines don't seem to depend on what the liquid is, just how unnaturally or forcefully you move it.

Good points, and I hadn't thought of eyes of the bat. I wonder if you could use a version with target smell to direct the covenant's hounds :laughing: