Troll Lord Games

Excerpt from my house rules wrote:
Spell casters must inform the CK (DM/GM) before initiative is rolled if they intend to cast a spell and what that spell will be. If the spell caster is successfully assaulted (i.e., hit by a weapon, affected by a harmful spell effect, etc.) before casting the spell, the spell caster must make a SIEGE check to determine whether their concentration has been broken. Wizards and Illusionists must make a check against Intelligence and Clerics and Druids must make a check against Wisdom. The Challenge Class will be the Challenge Base (12) + the spell level of the spell being cast by the PC + the amount of damage, if any, taken by the character. The PC gets to add their level to their SIEGE roll as well as their attribute bonus, if any. If the PC passes the SIEGE check, the spell is disrupted, but the PC does not lose the spell (meaning the PC can cast the spell in a later round). If the PC rolls a natural 20 on the SIEGE check, the PCs concentration is not affected at all and the PC will cast their spell that round. If the PC fails the SIEGE check, they lose the spell entirely and must rememorize it before it will be available again.

Example: Buddy is a third level wizard. Before the PCs roll initiative, he declares his intention to cast magic missile, a 1st level spell. Buddy rolls a 1 for initiative and will act last in this combat round. A bugbear hits Buddy with a club and does 3 hit points of damage to Buddy. When Buddys turn comes around, he must make a SIEGE check against Intelligence to determine whether his concentration was broken. His challenge class is 16 (12 base + 1 for the level of the spell (magic missile) + 3 for the hit points he lost in the attack). Buddy rolls a 13, but due to his high intelligence attribute bonus of +2 and adding his level (3) to his roll, he gets a modified 18. This is higher than 16, but not a natural 20, so his spell is disrupted, but he can cast magic missile again next round without having to rememorize the spell.

NOTE: If a spell caster is affected by a magical effect that would prevent the PC from casting the spell altogether (e.g., the PC is paralyzed and the spell has a verbal or somatic component), the PC will automatically lose the spell without a SIEGE check.

Fizz wrote:
Actually, this is semi-related to thsoe of us who have tried spellcasting as a Siege check.

Instead of using the spell level in the CL, use twice that. After all, you can't cast a spell of level X until you're level X*2 - 1. It makes sense that the CL increases at twice the rate of spell level.

And it'll definitely keep those checks from being too easily made.

-Fizz

serleran wrote:
Any system you implement is a bonus to the caster because, by the rules, any hit during casting automatically disrupts the spell... so, even giving them a "need to roll a natural 20" is a benefit they would not ordinarily have. After that, you can decide how easily you want them to keep their spells. Sounds to me as if you'd rather them not drop spells too often. To that effect, I would make it a non-SIEGE check akin to SR: start it off at 6 + spell level - attribute modifier. The caster has to roll above this on a d20 to keep the spell.

Joe wrote:
IMHO 3.5 and the skill concentration makes attacking a spell caster almost a non tactic.

Every spellcaster worth his guff maxes out of concentration which makes for an easy die roll.

serleran wrote:
Any system you implement is a bonus to the caster because, by the rules, any hit during casting automatically disrupts the spell... so, even giving them a "need to roll a natural 20" is a benefit they would not ordinarily have. After that, you can decide how easily you want them to keep their spells. Sounds to me as if you'd rather them not drop spells too often. To that effect, I would make it a non-SIEGE check akin to SR: start it off at 6 + spell level - attribute modifier. The caster has to roll above this on a d20 to keep the spell.