Arcane Spell Failure - Is It Silly?

[Hardhead]

I don't really think it is overpowering in and of itself. I think it is a definite power boost especially when you start looking at more exotic armor twinks (something I do not excel in nor try to excel at). However, I think that this house rule will encourage wizards and sorcerers to multi-class into fighter types too often. The benefits of starting as a fighter and then multiclassing into wizard after one level are just too great: weapons, armor, shield, bonus feat, higher HP, equal (albeit different) skills, and now no ASF (resulting in higher AC) at the cost of one caster level.

Actually, it's a +8 bonus net. You don't get the Mage Armor anymore, sure, but with a level of Fighter, you get heavy armor prof and tower shield prof. Sure, it gives you a -2 to attack, but that's not a big deal to wizards. And at mid levels, you can definitly enchant them for at least +2 more apiece. That's a +16 AC bonus from just armor and shield bonuses. Waaaay higher than what a wizard is used to.

Sure, your movement is only 20', but don't forget that wizarding staple spell, Fly.

OTOH, if I were a wizard with these rules, I'd probably go with a level of Cleric. Two good saves, two possibly very nice domain abilites, and cleric spell-trigger items are not usable to you.

 

[T-Bone]

A few quick thoughts.

Heavy armor would and should impede a weak character. Most mages don't have high strength scores, so that could keep them from armor.

Making them take the armor proficiency feats, to me, is a good balancing mech.
The only glitch is the "I take one level of fighter".

Here's a fix, Fighters & Clearics gain Light Armor Proficiency at 1st, Medium Armor Proficiency at 2nd, and Heavy Armor Proficiency at 3rd. Instead of all 3 at 1st. I think this would help balance ALOT of multiclassing issues. Besides, a 1st or 2nd level fighter shouldn't even have enough money to buy heavy armor yet.

Another thought. Casting spells could be a spellcraft check, with armor check penalties. DC10+spell level. You could also get your INT bonus to this roll. (or CHA for sorcerers.) If the check is too easy, you could rule that Armor check penalties are 2 greater when it comes to spellcasting. (AKA -2 circumstance penalty/DM's best friend rule).

Again, you would want a high spellcasting ability modifier so that you can successfully cast spells, you would want a reasonable INT score, and thus skill points to max out Spellcraft. This might mean that you have a lower Strength score, and thus be encumbered, worstening your spell check. Characters who max out Int & Str, would probably have low CON & DEX scores, and be suseptible to Will Saves. Having to burn multiple feats or multiple levels in fighter to get to the heavier armor types would mean they would have to be fairly up in levels to even do this, which is another balancing factor.