Post/Author/DateTime	Post
#1 Barky Feb 25, 2015 20:14:48	I'd like to add the concept of "cooperative casting" to my own campaign.     It would work like this: if three or more clerics of the same deity worked together, they could cast a single spell of a higher level than they can individually.   Maybe three 3rd level clerics could cast as a single 6th level cleric Maybe it takes twice the casting time (two rounds instead of one) Maybe they can't take any other actions while they do this. Maybe the spell can be disrupted by taking one of them out. Maybe adding more than three makes the spell stronger, or less likely to be disrupted. Maybe this only works for lawful deities This is just to add flavor, and to hopefully take the party by surprise. There are also reasons that fit into the style & plot hooks of my campaign. Having a cleric spell higher than the party would normally encounter, without the higher level cleric to go with it, may be interesting or dangerous without being outright deadly.   Any ideas how to do this and keep it balanced?
#2 Archon007 Feb 25, 2015 21:20:52	Whatever you do expect the players will want to do it too. Based on your reasons I'm not sure it's necessary. If it's a once in a while thing have the enemy use a scroll, magic item with 3 charges on it, etc
#3 Coredump00 Feb 26, 2015 3:45:44	I would not have any problem letting NPCs do this and not PCs, assuming it was a rare occurence.  If almost every NPC could do it....that would be different.   I also would not be as worried about balancing it, because you will be controlling it and thus keep it from getting out of hand.
#4 Kayal Feb 26, 2015 4:26:11	Barky wrote:
#5 DwarfLordSeven Feb 26, 2015 10:14:17	Some ideas:   1) I don't think you necessarily need to restrict this to Divine Casters.  There is no reason a group of wizards or warlocks shouldn't be able to channel their power together to cast more powerful magic.   2) There are some hints related to this in the monster manual already.  See the entries on Aarakocra (Summoning Air Elementals) and Hags (Hag Covens)   3) Consider whether you want this ability to be available to PCs also or only to NPCs.  If available to PCs, how do they gain the ability to do it?  Do they need a feat?  A special item?  Are there just scrolls laying around that have alternate casting instructions for spells using more than one caster?   4) Maybe instead of casting higher level spells, when casters group-cast they can only cast low-level spells at higher levels (increase the spell level by 1 for each caster after the first).    5) I would consider probably also increasing the casting times and requiring concentration checks while casting, to give a chance for these more powerful spells to be interrupted.   Maybe multiply the casting time by the number of spell levels higher than those you can normally cast.  eg: if you can cast 2nd level spells normally, a 3rd level spell with a casting time of one action might take your whole turn (action, bonus action, move, and you can't take reactions until your next turn), and a 4th level spell might require you to concentrate for one turn (taking no actions or moving) and also use up your whole next turn.
#6 Barky Feb 26, 2015 18:13:54	Thanks for the input.   Here's where I'm going with this:   For one of my major campaign set pieces, I envision a room full of cultists chanting away, which will lead to something very bad. The party has to get in the fortress and get in range to disrupt it before something horrible happens. Of course the chanting cultists are heavily guarded ...   I don't want that to come out of nowhere, so I want to use cooperative casting as elements in encounters as the party moves through the campaign. By the time they get to this big battle at the higher levels, they will know full well what chanting means, and understand the mechanics I create so they can figure it out for themselves without me having to explain it.   This means I have to use it at lower levels. The bonus is this can make monsters more powerful than their legacy suggests. My players have played for years and years, but I've never DM'd for them before, and I feel both obligated and challenged to keep them guessing. We also all play in another campaign (I'm a player in that campaign, and that DM is one of my players), so I'm trying to keep it different from that campaign. "How can these cave goblins cast flame strike?" is one small part of that attempt.   I am focusing on divine casters because, thematically, I can conceive of a deity (especially a lawful one) rewarding such commitment and unity of purpose with greater power. It seems more "normal" for religious groups to do that instead of bookworms who tend to study in isolation. Plus there's no need to "know" the spell, it's granted by the deity. This is totally my own take on it, of course.   Some crude thoughts on building the encounters: Three is a number often used in drama, so three casters minimum Together they can cast spells as a cleric equal to the sum of their current level. Three 3rd level casters can cast as a 9th level cleric, so they can cast a 5th level spell. To keep it from becoming overpowered, it's only the level-sum of the top three casters in a group. Extra casters only mean non-damage improvements, like extra AoE or longer duration, or maybe that cure becomes mass cure. More than three also acts as a buffer against disruption of the spell (next bullet). Casting time is 2x normal. Spell can be disrupted by breaking concentration via those rules. Three casters must be concentrating at the end of the spell or it doesn't work. I like DwarfLordSeven's comments on this, I have to think about that.  The problems I see are: I find 5E to be pretty deadly (so far, we're still only 3rd level), I don't want to make the casting time too long. I have to build encounters where the cooperative casters have a chance to get that spell off. Maybe they sit on a ledge high up the cavern wall, or they all have rogue levels and can hide until they're in position, or whatever. Their "supporting cast" has to array themselves to protect that "cleric circle" from disruption. This should be part of their culture, I have to remember that they will do this as a matter of course. The dreaded AoE spells the players cast will be problematic. I have to let that happen, of course, and I don't want to metagame it to intentionally screw over the players. I just need to work in appropriate yet fair counter-strategies.   A problem I actually don't see is having the players demand to do it. First, you'll rarely have three clerics of the same deity in a party. Second, the players will be sitting ducks during the casting, I don't see they wanting to do that.     tldr; I'm just trying to find ways to throw different things into the campaign. I'm just looking to see if I can make it cool, interesting, challenging, or surprising for my players without causing a table revolt.
#7 Oriet Feb 27, 2015 11:57:22	I could see arcane cultists also forming magic circles, but it does make sense that divine casters would do such more often (as they already organise around their deity and regularly cooperate in doing so, whereas arcane casters generally don't have such non-magical rituals/practices).  I've done similar things in the past with NPCs, though more as a point of flavor for some effect or sommoning of a creature instead without any framework built for replicating such.   That said, I like the idea of a magical circle of casters augmenting current spells beyond their normal limits, though casting a higher level spell also makes sense. I would likely treat such as ritual castings of the spell (even if it doesn't have a ritual version in RAW), probably taking 10 times as long (so a 1 action spell takes 1 minute to cast, a spell that takes 10 minutes would take 100 minutes, or 1 hour 40 minutes) if no spell slots are expended (or normal time if everyone in the circle expends the needed spell slot), allowing casters to enter and leave the magic circle (so long as they never go below the minimum number needed to cast the ritual), and also need to maintain the circle for maintaining concentration on it, though with such I would also say that concentration is only limited by how long they can maintain their magic circle.      A "quick and dirty" mechanic for determining how long it takes to cast a magic circle spell (beyond the 10 times listed) could be that each doubling of a feature, such as spell range or area of effect, each increment of increase in spell level it counts as being cast at (possibly allowing for "boosted" effects to exceed 9th level), or each spell level above the lowest caster's maximum spell level, adds increases the mutliplier to the base casting time (with a base multiplier of 1).  This would mean circle-casting fireball for double range would take 2 minutes (without expending spell slots), while casting earthquake (8th level spell) at triple range (multiplier increase of 2), for double the area of effect (multiplier increase of 1), and by a circle of 13th level clerics (highest spell slot of 7th level, so multiplier increase of 1) would take 5 minutes (multiplier of 1+2+1+1=5).  Such casting isn't useful in the standard skirmish fights a party has, but would work wonderfully during a seige or battlefield warfare.  Even if you multiply that result by the spell's level (making it 6 minutes for the example fireball or 40 minutes for the example earthquake) you still have excellent warfare spells, and groups of spellcasters would likely be highly scrutinised or illegal so as to prevent such spells being cast in a city.     Edited to add: While such mechanics would allow a group of 1st level spellcasters to cast wish with a casting time of 8 minutes (8 levels higher than their 1st level spells; 72 minutes if multiplied by the spell level), I would say that any negative drawback would be suffered by each caster that takes part in the magic circle.   If a caster ends up never being able to cast wish again, I would say they also cannot take part in a magic circle trying to cast wish.  This would definitely reign in spell abuse, even by NPCs, though it could still happen.