What's the CR of a...

[Ragmon]

Should a creature be larger than the area enclosed by the barrier (10 ft. radius), any part of it that lies outside the barrier is
unaffected by the field. A fire giant is 12 feet tall, so part of it would stick out unless it continuously stooped - enough to blast it with a cone of cold...

And if you could wait about 110 minutes or so, you could come back to fight the giant. It's not like someone could cast permanency on an anti-magic field...

It would depend where the DM decides the field is centered. Cause if lets say if the center is at the giants center of mass then it can clearly fit into the field.

But if the field is centered just under the giants feet then your right.

 

[(Psi)SeveredHead]

Sad reality: Some things happen "because the DM said so."

<EDIT> Actually, the caster could have done it for as many Giants as he chose, using just two rings.

Step 1: Charge rings. He gets to put the Contingencyin at 18th level because that's the minimum needed for this particular use. (Yeah, it's a stretch, but it's the kind that DMs love to use).

Step 2: Hand Rings to a Giant.

Step 3: Giant triggers rings, and now has an Antimagic Field on himself, under Contingency.

Step 4: Giant hands rings back to caster.

Step 5: Go to step 1 as often as needed, until all Giants are charged.

The Giants don't need to have the rings on them at all when we fight. I don't know if our DM thought it through to this degree, but it is possible and he said that it happened, so...
</EDIT>

Given the amount of influence this 18th-level caster had on the encounter, their CR should be included in the fight. So not a CR 6+ trap, but CR 18+, plus flunkies plus environmental hazard.

 

[delericho]

Step 1: Charge rings. He gets to put the Contingencyin at 18th level because that's the minimum needed for this particular use. (Yeah, it's a stretch, but it's the kind that DMs love to use).

Per RAW, this doesn't work. Under the description for the ring of spell storing (actually, the minor version, but the normal and major versions don't change this), the DMG specifies:

"Each spell has a caster level equal to the minimum level needed to cast that spell." So, the contingency in the ring would be at CL 11 (it being a sixth level spell). There's no option given for charging the ring at a higher caster level, presumably to avoid abuses of this very sort!

 

[Greenfield]

Yeah, I know. I'm trying to account for something the DM said happened.

Could it be done with Craft Contingent Spell?

Alternately, a single Major ring with Quickened AntiMagic Field stored inside. Not quite as convenient as Contingency, but it fits what's possible.

 

[Stormonu]

Yeah, I know. I'm trying to account for something the DM said happened.

Could it be done with Craft Contingent Spell?

Alternately, a single Major ring with Quickened AntiMagic Field stored inside. Not quite as convenient as Contingency, but it fits what's possible.

Quickened adds +4 spell levels, so that'd make it a 10th level spell, not feasible unless you're using some UA metamagic variant or Epic spellcasting of some sort.

 

[Greenfield]

I don't thing the Quickening metamagic rod is from UA. I think it's frpm the DMG, page 234.

There are three variants, with the medium one being sufficient. (4th through 6th level spells).

But I've spoken to the DM and he's explained everything...

It happened because the DM said so.

Which brings us back to the monster CR.

For me, the final way to measure CR of some tricked out thing is to stand it up to a character of the appropriate class and see how it does.

Against spell casters of any kind, this thing is unstoppable. All they could do is avoid it and try to wait it out. It would end up leaving when the AMF went down. If the spell casters couldn't run away or hide effectively, it would pound them with boulders at range. They'd have to leave completely.

Against a decent archer it comes down to whether either one can kill the other before the run out of ammunition. 20 arrows at a D8 each, plus Strength and no magic would be unlikely to be enough to drop him. His boulders do more but ha can't carry more than a few, and any that miss simply keep going. Relative gravity realm being what it is.

That leaves a melee type. As I ran the numbers, a hefty Barb with a great sword, power attacking, can match the Giant at about 16th or 17th level.

That's not exactly in line with the argument that calls this a CR10, with an AMF trap thrown in for a total of CR 11.

Now, I could prepare a character designed for the situation, and drop the thing at less than 10th level. A Rogue with a Ring of Invisibility, a Quiver of Ehlonna and a decent magical bow (and maybe a bucket of Cure Moderate potions) could sneak-attack him to death before his AMF went down. Move within 30 feet, take your shot from outside his AMF, then next round vanish again and move. Skip a round as needed to heal. He'll fall in far less than the 110 rounds of his AMF.

And that's just off the top of my head, using PHB classes and DMG items.

But this isn't "Name that Tune", where we bid, "I can beat that monster in 5 levels or less." I'm just trying to figure a fair CR.

Oddly enough, the DM plans the encounters, but he leaves it to me to calculate the EXP and e-mail the rest of the group.

 

[delericho]

I don't thing the Quickening metamagic rod is from UA. I think it's frpm the DMG, page 234.

There are three variants, with the medium one being sufficient. (4th through 6th level spells).

But I've spoken to the DM and he's explained everything...

It happened because the DM said so.

Yep, there are a few ways to get an antimagic field into a ring of spell storing. But, as in this case, the one most likely to be encountered is, "the DM said so".

It's perhaps also worth wondering if this is one of those cases, like a troll with immunity to fire and acid, that the game technically supports but that the DM is recommended not to use.

Which brings us back to the monster CR.

For me, the final way to measure CR of some tricked out thing is to stand it up to a character of the appropriate class and see how it does.

Against spell casters of any kind, this thing is unstoppable. All they could do is avoid it and try to wait it out. It would end up leaving when the AMF went down. If the spell casters couldn't run away or hide effectively, it would pound them with boulders at range. They'd have to leave completely.

Against a decent archer it comes down to whether either one can kill the other before the run out of ammunition. 20 arrows at a D8 each, plus Strength and no magic would be unlikely to be enough to drop him. His boulders do more but ha can't carry more than a few, and any that miss simply keep going. Relative gravity realm being what it is.

That leaves a melee type. As I ran the numbers, a hefty Barb with a great sword, power attacking, can match the Giant at about 16th or 17th level.

That's not exactly in line with the argument that calls this a CR10, with an AMF trap thrown in for a total of CR 11.

Now, I could prepare a character designed for the situation, and drop the thing at less than 10th level. A Rogue with a Ring of Invisibility, a Quiver of Ehlonna and a decent magical bow (and maybe a bucket of Cure Moderate potions) could sneak-attack him to death before his AMF went down. Move within 30 feet, take your shot from outside his AMF, then next round vanish again and move. Skip a round as needed to heal. He'll fall in far less than the 110 rounds of his AMF.

Yes, but the CR of a monster isn't about how it stands up to an individual PC, it's about what makes it a decent challenge for a mixed party of four such PCs. So, if we have a Barbarian with decent Power Attack and a suitably stealthy Rogue willing and able to use his sneak attack and a Cleric who can heal them both, and a Wizard who can at least try something, what level do they need to be?

Also bear in mind that while the spellcasters' options are sorely limited by the antimagic field, they're not useless - summoning spells from the calling or creation subschools (where the latter has an instantaneous duration) can still be used without issue, or indeed they could just stick a wall of force around the giant and wait him out.

 

[Quartz]

And I can see the idea of doubling the Exp, except for one thing: For most of the party level 17 and 18), the monsters were worth literally nothing.

So nobody had Disjunction or Wish or Miracle?

 

[(Psi)SeveredHead]

Disjunction is a spell PCs never use because they're so equipment-dependent.

Wish and Miracle cost XP, and I wouldn't expect PCs to prepare it every day. Then again, I've never seen it cast in 3rd Edition. Only in 2e, where a PC spent days in game terms writing up a "perfect wish".

 

[Quartz]

Disjunction is a spell PCs never use because they're so equipment-dependent.

One of its explicit purposes is to break an AMS.

Wish and Miracle cost XP, and I wouldn't expect PCs to prepare it every day. Then again, I've never seen it cast in 3rd Edition. Only in 2e, where a PC spent days in game terms writing up a "perfect wish".

Ah, this is the big difference between 2E and 3E. Spending XP is actually a good idea in 3E. And I would expect any spellcaster with more than one 9th level slot to have Wish or Miracle in one of those slots, assuming it's available.