I am currently in a brainstorming process for potential spell effects and the purpose of this discussion is to come up with any missing effects, discuss the placement of spell effects, and other topics relating to how magic will work in this game.
In this concept, I made Spellcasting a set of skills that you spend ranks in to become skilled in, such as Spellcasting (alteration) or Spellcasting (destruction). The basic mechanic for casting a spell is making a Spellcasting check against a set difficulty number that you have to achieve to succeed in casting the spell. You add your rank in the Spellcasting skill, the appropriate attribute modifier, and any other relevant modifiers to a 2d6 roll to determine your check result. Pretty simple and fits the progression theme associated with the Elder Scrolls.
Anyways, here is what I came up with so far in terms of spell effects.
Alteration (Willpower-based) Spell Effects
Mage Armor (grants a bonus to your Defense rating [the result enemies must make on Combat checks to strike you in physical combat].)
Light (s/e) - placed this in alteration because it alters a property, not the mind of a creature.
Open Lock (s/e) - Alters the state of a lock, which is why this effect is not under thaumaturgy.
Ease Burden (otherwise known in earlier games as Feather; simply increasing max encumberance level)
Lock (the exact opposite of Open Lock)
Resist Elements (two parts to this; includes both ignoring elemental damage like fire or cold, but another spell like this could allow the character to live comfortably in the dead of winter in Skyrim or in the sands of Elsweyr in mid-summer).
Water Breathing (alters the property of a creature, whereas water-walking is thaumaturgy because it breaks the laws of physics).
High Jump (s/e) Simply grants a bonus on the Jump skill.
Fabricate (creates useful items out of raw materials in a fraction of the time it would take normally)
Transmute (change lead to gold, water to wine, etc)
Polymorph (shame this isn't in more modern Elder Scrolls video games, eh?)
Paralyze (had trouble deciding whether this belonged to Alteration or Illusion. Then I figured that it more affected the target's nervous system rather than the target's perception.)
Burden (opposite of Ease burden)
Swift Swim (simple bonus on the Swim skill)
Resist Magicka (grants a bonus on reactions [D&D equivalent of saves] vs magic)
Enlarge (makes things bigger)
Reduce (makes things smaller)
Animate Object (very amusing effect, try it on suits of armor )
Darkness (the opposite of light)
Alter Self (granting yourself a special characteristic that grants you a benefit, such as werewolf claws or dragon wings)
Petrification (turn creatures to stone of course)
Free Movement (frees creatures from binding effects)
Telepathy (s/e)
My next post will cover Conjuration effects.