Can I summon a shadow demon and provide the components for Magic Jar?

[Jeon]

Full example:

A wizard summons a shadow demon. Normally a summoned creature can't cast a spell with an expensive component cost (what would count as too expensive?). However, what if the wizard gives the shadow demon the spell component (a gem or crystal worth at least 100 gp)for magic jar?

Does a summoned shadow demon not have access to the magic jar spell at all?

[Chris Kenney]

Technically, no - the Shadow Demon doesn't have access to the Magic Jar for purposes of Summoning. Thematically, Summon Monster is kind of a "pre-fab" binding contract. You quickly put out a notice for a short-term service on the appropriate plane and give up a portion of your spell energy (represented as the spell slot) and get services from the relevant creature for a very short duration. The monster gets the energy (and probably the improvements from your Augment Summoning feat for a period of time after returning to its' home plane) in exchange. You haven't 'paid for' the use of that magic jar, so the Shadow Demon has no obligation or desire to use it on your behalf, especially since he gets to go home with no strings attached in a few minutes at most.

If you want summoned critters to use spells on your behalf, you're going to need to look at Planar Ally and Planar Binding. Which, depending on the spell, may be more or less expensive in GP than just getting a wizard or cleric to do it for you.

[Jeon]

How do i begin...I happen to have a permanent summon monster as a servant. Seriously, look at the antipaladin archetype from the advanced player's guide. I didn't think someone would give as much consideration as you have to the theme and mechanisms behind the spell so I didn't give a full background to the question. I expected a yes or no with a very short reason.

Thank you for going past my expectations in your answer.

Essentially I have a summoned monster that will be with my character for weeks or months and might have some role play with my antipaladin. Would it make sense for me to provide the creature a spell component?

Is a summoned monster truly incapable of using spells with an expensive component cost?

Edit: I have a broader problem with this same servant in this thread if you are curious http://paizo.com/threads/rzs2pmxn?Antipaladin-feature-confusion

[Devilkiller]

Summoned creatures can certainly use spells and spell like abilities other than those specifically precluded.

The question of shadow demons and Magic Jar is kind of interesting aside from that of summoning though since shadow demons probably wouldn't possess a gem to put their life force into. They also wouldn't have any physical body to leave behind. The groups I've played in have always assumed that the shadow demon's power works a lot like Magic Jar but doesn't require the focus. I guess there's nothing specific in the RAW which says this, but it seems like a good house rule to me. Otherwise I guess that shadow demons either have 100gp gems they somehow carry around despite being incorporeal or can't actually use their Magic Jar ability (both of which seem silly to me)

I've never really considered whether the fact that Magic Jar normally requires a gem or crystal would prevent a summoned creature from using it. Technically the Summon Monster spell mentions that the summoned creature can't use spells which require "expensive material components" while Magic Jar requires a focus rather than a component. I'm not sure if that should make a difference.

[Interzone]

The Magic Jar ability is a spell-like ability, spell-like abilities never require any material/focus/etc components.
So the whole issue of the gem is irrelevant.
The only condition on summoned creatures (even if they are permanent) as far as casting is they can't use dimensional magic (such as plane shift/teleport/etc) and they can't summon (so your shadow would never be able to use his ability to summon more shadows) but other than that anything he has is fair game.

For reference: (from Universal Monster Rules)

Spell-Like Abilities (Sp) Spell-like abilities are magical and work just like spells (though they are not spells and so have no verbal, somatic, focus, or material components).

[Devilkiller]

Thanks for pointing out that rule on SLAs. It is good to know that the shadow demon can indeed use its big ability!

It isn't just dimensional magic and summoning which is prohibited for summoned creatures though. To quote the rules

PRD wrote:

Creatures summoned using this spell cannot use spells or spell-like abilities that duplicate spells with expensive material components (such as wish).

As I'd mentioned, Magic Jar has a focus rather than a component although I'm not sure if we're supposed to make such a fine distinction or not. It also isn't entirely clear if 100gp is "expensive". I'd certainly allow a summoned shadow demon to use Magic Jar to "possess" somebody, granted that it would only last as long as the Summon Monster spell. I'm not 100% sure if that's the right ruling though.

[Darksol the Painbringer]

RAW, I agree with the others in that you cannot provide an expensive component for a spell-like ability due that the spell-like ability cannot utilize them to begin with, meaning that by rights and technicalities, spell-like abilities cannot have material components.

The general consensus for "expensive material components" would be thousands of gold; then again, expensive in general varies from level to level. Taking the example the book cites in terms of "expensive material components" (the Wish spell), which costs over 1,000 gold for sure, taking a 100 gold gem in comparison is a minor fraction of the cost, and would most likely not warrant the spell component being under the listed definition.

With that said, let's review:

Summoned Shadow Creature with Magic Jar spell-like ability (normally has a 100 gold piece material component to cast, but is not included as spell-like abilities have no verbal, somatic, or material components, and no focuses).

Summoned Creatures cannot cast spells such as Teleportation, Dimension Door, Plane Shift, etc. or spells that have costly material components (e.g. the Wish spell, costing ~1,000+ gold pieces).

You would technically not have to bother with the component, because the SLA wouldn't have it, and it isn't really a costly component in the first place.

I hope this helps!

[Marthkus]

Magic jar does not have a material component. It has a focus. No restriction for summoned monsters and focuses.

[AnnoyingOrange]

expensive in this context is anything without negligible cost, be it 10 gold, 50 gold or 25,000 gold.

It does not matter here though, magic jar has no expensive component and the shadow demon's ability is more like possession it deviates quite a bit from the spell. In the end it remains a GM's call though.