Thieves' World Spell System

[Yogibear41]

Has anyone ever played with the variant spell system from the Thieves' World books? Did you like it? Any thoughts on it? Stumbled across this book the other day and I must say I am interested in this system, but am afraid it could break things at a higher level. (break as in a bad way for the players, not a good way)

For those unfamiliar with the system, to break it down simply from how I understand it, everyone has unlimited spells per day(but a limited number known), but spells can potentially take lots of rounds(probably on average between 1 to 5, but potentially more) to cast(relative to spell level) depending on how dice rolls go, the level of the character, and his ability score modifier. Using this system lower level characters can even cast higher level spells, for example a 1st level character could potentially pull off a 6th level spell given several minutes to cast it(and if he has knowledge of the spell), but there is a pretty good chance it will kill him as well.

[jiriku]

In general, such a system wouldn't do well mechanically in a d20 environment.

Unlimited spells per day in a d20 environment is potentially trivial or game-breaking, depending on which spells we're talking about. Unlimited prestidigitation or unlimited detect magic is nothing to get excited about. Unlimited fireball or lightning bolt is nice but can be balanced. Unlimited teleport or unlimited fabricate tears the game world into itty bitty pieces and reassembles it into something that doesn't even remotely resemble the Thieve's World novels.

Casting time is an ineffective balancing tool for spells can be cast when there is no particular urgency. For spells cast during combat, it's still hard to judge the usefulness of a particular spell and while casting time adjustments can work, they're a clumsy balancing tool (although not without usefulness).

Random chance of death is a terrible balance factor. If the player rolls well, his character does not suffer, and balance is not achieved. If the player rolls poorly, his character is dead rather than balanced. Balance is still not achieved. A random chance of danger or a random chance of plot complications would work better. For example, a spell that summons and binds a demon, but might have a chance of summoning the demon while failing to bind it and instead making it angry, can work well. Likewise, a spell that might change an NPC's attitude from neutral to friendly, but could change it from neutral to unfriendly if it fails, could work.

Access to spells of much higher level than you would normally have is a poor idea unless all classes are well-balanced with respect to each other and all classes have equal ability to occasionally tap their own higher-level powers. For example, if the bard could occasionally command a mob through his charms, and the thief occasionally step across the most difficult of nightingale floors, then perhaps it's alright if the wizard can occasionally exceed his own limits. The optional action point system is a good way to give players a currency they can collect and spend for the chance to do this. However, you've got a BIG PROBLEM in most d20 games because the classes are not well-balanced with respect to one another -- you'd want to fix that.

[Yogibear41]

Well the chance of death isn't really random, you take a certain amount of damage for casting the spell, which would generally be enough to take out a low level spellcaster, I should have been more descriptive. So you basically know how much damage you are going to take. There are some rules about critical failures that can happen when casting any spell, but they are more akin to the critical failure chart of melee/ranged combat in the dragon compendium, although since they are spell related they tend to look a little worse.

you also take nonlethal damage when you cast "safe spells" and the cure spells only convert lethal to non-lethal except for the heal spell. So i guess you are limited by your HP to how much you can cast in a day. It only appears to be unlimited. Granted non-lethal heals a lot faster.

[Necroticplague]

you also take nonlethal damage when you cast "safe spells" and the cure spells only convert lethal to non-lethal except for the heal spell. So i guess you are limited by your HP to how much you can cast in a day. It only appears to be unlimited. Granted non-lethal heals a lot faster.

Considering Vigor spells, the troll-blooded feat, silithar healing blood, the Feral template, the Shadow template all exist to easily turn nonlethal damage into not-damage (just off the top of my head), this is a trivial limit to get around. Sounds a like a system that actively punishes you for trying to use it normally (casting spells to help allies in-combat), and instead rewards you abusing it (prepping spells above your level normally available during your downtime).