Here's a rather interesting question to ask,
"If non-damaging spells such as buff spells and other spells were given the ability to 'crit' on cast, would it break or hurt the game a lot?"
When I think about it, I realize it can have a interesting effect on spells in the game. Of course, it would increase the love of arcane lore even more, and maybe specific types of spells less, but elemental spell crits can be effected by it as well, depending on what spell you cast. The way spell crits work is a bit wierd, and depends on the spell. To break it down, it would go like this if a spell were to crit(Beware: Long wall of bullets ahead!):
- Buff spells such as jump, neutralize poison, all shield spells, protection from elements, resist energy and more would either go up a tier if it is not maxed, or if it is maxed, would act as if it extended, which would stack with extend. (I was thinking about adding +10 to either jump or resist even if it was maxed but thought against it.)
- Web, charm, knock, all dispel magic, non-damaging AoE spells, mordenkainen's disjuction, suggestion, hold spells and more would have a higher DC multiplied by the + damage that a crit adds(For example, greater arcane lore would increase the DC by 25%)
- Zeal would increase the doublestrike change based on the % damage increase of the crit.
- Remove curse, paralysis, fear and disease would give a 2 minute ward against its respective removal, regardless of type of arcane lore.
- Spell resistance would increase the resistance given by the % damage increase that arcane lore gives.
- Fire and cold shield would increase the absorb rate taken by the % damage increase, but last shorter based on how high the % damage increase was on the lore. (For example, greater arcane lore would reduce the duration by 25% and increase absorption by 25%, while major fire lore would reduce the duration by 50%, but increase damage absorbed by 50%. Damage absorption factors are multiplied, not added.)
- Angelskin gives double the DR, regardless of type of arcane or good lore.
- Divine power gives a +8 STR bonus instead of +6, regardless of type of arcane lore.
- Obscuring mist, fog cloud and solid fog will have their vision obstruction and other effects, if any, increase in intensity based on the type of arcane lore used.
- Invisibility will turn into 'greater' invisibility for a brief period of time(1d10 +1 per caster level, up to 30 seconds) where any attack or action performed will not give it away. However, after this time expires, it downgrades to regular invisibility, regardless of type of arcane lore.
- Greater heroism, virtue, stalwart pact, aid and False life gives double the hitpoints given, regardless of type of arcane lore.
- Power Word: Kill bypasses an opponents spell resistance on a crit. Stun turns it into a helpless type of stun, and blind doubles the duration, regardless of type of arcane lore.
- Symbol of stunning turns it into a helpless stunning. Weakness increases the STR damage based on the type of arcane lore used, and death doubles the energy drain gained, regardless of type of arcane lore.
- Summon spells gain a augment summoning ability, even if they have one, regardless of type of arcane lore.
- Raise dead restores 50% of hitpoints instead of 10%. Resurrection restores all hit points and True Resurrection gives temporary hitpoints equal to 10% of the targets HP, regardless of type of arcane lore.
- Death pact eliminates the -2 con penalty, regardless of type of arcane lore.
- Sleep and Deep Slumber allows you to make hits without automatically awakening the monster, although there is a chance of awakening it per hit(50% for arcane lore, 25% for greater arcane lore, 10% for major arcane lore and 5% for superior arcane lore.)
- Bestow Curse, doom, bane and crushing despair increase the penalties given based on the type of arcane lore used.
- Dimension Door would double the duration it remains open upon the caster leaving, regardless of type of arcane lore.
- Fear-type spells paralyze the target with intense fear, meaning it stays in place instead of running around.
- Flame arrow turns the arrows into flaming burst arrows.
- Ghoul Touch makes the target 'helpless', regardless of type of arcane lore.
- Lesser Restoration doubles its stat restoration and restores one negative level. Restoration restores 1d4 negative levels, and greater restoration turns into a AoE spell, regardless of type of arcane lore.
- Teleport eliminates all rolls made to see if you 'fall from the sky'. Greater teleport gives players the ability to choose another teleport location if they do not wish to go to the location offered, regardless of type of arcane lore.
- Holy sword allows you to retain the sword through one logout session, regardless of type of arcane lore.
- Lesser and regular globes of invulnerability increase the caster level of spells blocked by one, regardless of type of arcane lore.
- Masters Touch allows the weapon to retain its proficiency granted for one rest period, regardless of type of arcane lore.
- Ray of exhaustion exhausts the target even if it succeeds on a save, regardless of type of arcane lore. Enfeeblement increases the STR damage based on type of arcane lore.
- Seek eternal rest increases its hit die based on type of arcane lore.
- Shadow walk decreases the blurry visual effects based on type of arcane lore.
- Snare causes the target to be slowed on a successful save, regardless of type of arcane lore.
- Stone to flesh turns the stone into stoneskin instead, giving DR and duration based on the caster level of stone to flesh, regardless of type of arcane lore.
- Tenser's Transformation gives +6 instead of +4 to stats, regardless of type of arcane lore.
- Word of recall gives you the option of choosing a teleport location after you teleport from the regular teleport list.
*Phew* Hope I didn't lose any of you on my long wall of bullets(Or text, if you will call it that.). Anyways, the purpose of spells 'critting' is more or less supposed to be a 'bonus'; not a integral part of the spell. I may or may not have messed up a bit designing how a spell should crit if it does, but its a bit weird trying to design non-straight damaging spells to 'crit', so to speak. Not to mention, this doesn't cover every spell, but it gives you a general idea that some spell effects are the same, others can be a bit different. It's definitely something cool that can be experimented and even implemented someday. Opinions?