CR Increase For Losing Spell Levels

[Afgncaap5]

Thought I'd get a few quick opinions on this: let's say you're about to take on a Minotaur, but the Minotaur's maze is a magical location that causes magic to require more "effort" to cast (effectively requiring all spells to be cast in a slot one level higher than normal.) For prepared casters, they can still cast the spells they've prepared, but it uses slots from higher levels instead of the slots they prepared the spells in. (And with only a Cleric 2/Fighter 1 and a Sorcerer 4 to deal with, prepared casting won't be a huge concern. Would you boost the CR of this? Or the XP given?

I may add a second Minotaur since the group has been steadily growing and is now taking out CR 7 challenges when they should be finding CR 4 challenges to be level appropriate. Or I may ask someone else to take half the people to another side of the room to run their own game. But that's not important right now; do you think a magical quirk that makes spells require higher spell slots would warrant a boost to CR?

[Crake]

Thought I'd get a few quick opinions on this: let's say you're about to take on a Minotaur, but the Minotaur's maze is a magical location that causes magic to require more "effort" to cast (effectively requiring all spells to be cast in a slot one level higher than normal.) For prepared casters, they can still cast the spells they've prepared, but it uses slots from higher levels instead of the slots they prepared the spells in. (And with only a Cleric 2/Fighter 1 and a Sorcerer 4 to deal with, prepared casting won't be a huge concern. Would you boost the CR of this? Or the XP given?

I may add a second Minotaur since the group has been steadily growing and is now taking out CR 7 challenges when they should be finding CR 4 challenges to be level appropriate. Or I may ask someone else to take half the people to another side of the room to run their own game. But that's not important right now; do you think a magical quirk that makes spells require higher spell slots would warrant a boost to CR?

The system you have in place doesn't really feel like a good way to handle what you want to achieve in 3.5. As you can see, prepared casting would be quite the issue (and clerics are prepared casters, so it will still be a concern), since spells go into slots, so using up a higher level slot to cast a lower level spell doesn't really make much sense, especially when you consider how it would work for casting a spell inside the area, then moving out.

A better way to handle it perhaps would be that anyone who can cast magic that enters the area is treated as having either 1 or 2 negative levels for the purposes of spellcasting, with these negative effects being removed upon leaving the area. What this means for prepared casters is that they lose access to 1 or 2 of their highest level prepared spells, and get -1 or -2 caster level, and for spontaneous casters, they lose access to 1 or 2 of their highest level spells and also a -1 or -2 penalty to caster level.

As for CR increase? Either way I'd say that's worth probably a +1 to the overall CR of the encounter (so 2 minotaurs at CR 4 a piece would be an EL of 6, +1 from that for 7).

[Afgncaap5]

The system you have in place doesn't really feel like a good way to handle what you want to achieve in 3.5. As you can see, prepared casting would be quite the issue (and clerics are prepared casters, so it will still be a concern), since spells go into slots, so using up a higher level slot to cast a lower level spell doesn't really make much sense, especially when you consider how it would work for casting a spell inside the area, then moving out.

A better way to handle it perhaps would be that anyone who can cast magic that enters the area is treated as having either 1 or 2 negative levels for the purposes of spellcasting, with these negative effects being removed upon leaving the area. What this means for prepared casters is that they lose access to 1 or 2 of their highest level prepared spells, and get -1 or -2 caster level, and for spontaneous casters, they lose access to 1 or 2 of their highest level spells and also a -1 or -2 penalty to caster level.

As for CR increase? Either way I'd say that's worth probably a +1 to the overall CR of the encounter (so 2 minotaurs at CR 4 a piece would be an EL of 6, +1 from that for 7).

Ah, yes, that'd be a much better way to handle that. Thanks!

[herrhauptmann]

Thought I'd get a few quick opinions on this: let's say you're about to take on a Minotaur, but the Minotaur's maze is a magical location that causes magic to require more "effort" to cast (effectively requiring all spells to be cast in a slot one level higher than normal.) For prepared casters, they can still cast the spells they've prepared, but it uses slots from higher levels instead of the slots they prepared the spells in. (And with only a Cleric 2/Fighter 1 and a Sorcerer 4 to deal with, prepared casting won't be a huge concern. Would you boost the CR of this? Or the XP given?

I may add a second Minotaur since the group has been steadily growing and is now taking out CR 7 challenges when they should be finding CR 4 challenges to be level appropriate. Or I may ask someone else to take half the people to another side of the room to run their own game. But that's not important right now; do you think a magical quirk that makes spells require higher spell slots would warrant a boost to CR?

Which book or ruleset are you operating out of?

What you're describing sounds sort of like the impeded magic trait of some planes. http://www.d20srd.org/srd/planes.htm#impededMagic
The fact that your custom effect only affects 1 character; I think a .5 CR increase would be more than enough. It may also make the cleric/fighter think you're after him specifically, since he can now only cast his 0 level spells. And he's the only one affected.

How big is your group? If it's 8 players or more, you might want to just have two separate games. Splitting and reforming the group in the middle of a game can be a big pain in the butt; there's a whole host of balance issues to work out too. Will the split be random? Will the players be choosing teams?

Do you have a co-DM already picked out? Is it one of the players? Will that player put his character into passive mode to run the fight? Or temporarily be both DM and PC?

[Afgncaap5]

Which book or ruleset are you operating out of?

What you're describing sounds sort of like the impeded magic trait of some planes. http://www.d20srd.org/srd/planes.htm#impededMagic
The fact that your custom effect only affects 1 character; I think a .5 CR increase would be more than enough. It may also make the cleric/fighter think you're after him specifically, since he can now only cast his 0 level spells. And he's the only one affected.

How big is your group? If it's 8 players or more, you might want to just have two separate games. Splitting and reforming the group in the middle of a game can be a big pain in the butt; there's a whole host of balance issues to work out too. Will the split be random? Will the players be choosing teams?

Do you have a co-DM already picked out? Is it one of the players? Will that player put his character into passive mode to run the fight? Or temporarily be both DM and PC?

We're using basic 3.5 rules, though there are a number of books that don't quite fit the game world so I'm only dipping here and there as needed.

I thought about Impeded Magic, but that didn't really fit the flavor of the location. The maze is a realm where magic isn't prevented from working so much as it actively breaks down.

And there's a second GM established. I doubt we'll get to 8 players, we'd need at least two more regulars for that to happen (currently only dealing with 6 plus myself), but if we hit that point he said he'd be willing to step up after I asked him.