Here is the URL to his work in progress: http://www.foundationsedge.net/myspecialpages/spellresearch/SpellReseach.html.

In summary, he seems to have demonstrated that the damage roll of a spell works by having a "base damage" (see the table below) and then your Magic Bonus (MB) determines how much extra damage you could inflict.

Spell Damage = Base Damage + (Magic Bonus x Level of Spell)

Here's an example. Call Lightning has a base damage of 26-73 HP per cast. If you have a MB of 3, since Call Lightning is a level 5 spell, you could inflict an extra 3 x 5 = 15 damage, increasing the range to 26 - 88. The minimum never changes though, only the maximum. This, obviously is NOT how a weapon works.

Now, pop a Potion of Wisdom, and you get +2 MB. This makes the damage range of Call Lightning expand to 26 - 98. An extra +10 per cast! So, the higher level you the spell is, the more a change in MB affects it.

Magic Bonus (MB) is determined by your INT and other items. However, it has nothing to do with your level. A level 40 mage with 18 INT has the same MB as a level 1 mage with 18 INT. Based on his results, it seems that level doesn't matter, only MB does. However, he only had 3 different levels in his results, and his research is directed towards MB not SP, so don't interpret anything too deep by that.

This is a work in progress (and determined by experimentation, so the numbers below may not be perfect. Don't read TOO much into it.) These are all corrected to reflect the effects on 0% MR. Remember that MR reduces this damage, and so does Elemental Resistance.

Spell	Level	Base Damage
Energy Bolt	1	1-13
Ice Dagger	1	2-13
Wind Shuriken	1	2-16
Fire Arrow	2	2-12
Stalac	2	7-11
Lightning	3	10-33
Frozen Cloud	3	14-26
Fireball	4	8-29
Earth Jail	4	16-24
Cone of Cold	5	33-58
Call Lightning	5	26-73
Eruption	6	41-57
Sunburst	6	37-79
Freeze	7	22-71

Good job, AlFansom!