I’ll admit my knowledge of D&D comes mostly from reading The Order of the Stick so bear with me if I’m a little fuzzy on the details (and bear and fuzzy are not intended as puns).
You’re a magic user in the D&D world. You’re confronted by an enemy so you cast a spell. You choose to summon an animal to fight the enemy.
How does that work? Not the magic end - I’m asking about how it works from the animal’s point of view.
Is the animal that you summoned an actual animal that was living in the real world or is it a platonic ideal of the animal from another plane of existence? If it’s a real animal, how was it chosen to appear? Does the spell just summon whichever animal is the closest to you? What happens if the closest animal happens to be a baby or sick or old? Is the animal compelled to fight on your side and how does it know who summoned it?
Does the animal go back to where it came from when the spell runs out? Does it still have an injuries it suffered during the fight? What happens if it is killed in the fight? Does the animal remember being summoned?
My players were afraid that they’d get in huge trouble by indiscriminate use of the Mount spell, particularly once they got powerful enough to summon mounts with tack, saddle, harness and saddlebags… which were full… so they went with the Shadow Mount spell (possibly not d20, don’t remember) which created the appearance of a horse, rather than grabbing whatever was nearby.
There are a number of different methods of achieving this end in a setting like those of D&D.
Spells of the Calling or Teleportation subtypes transport an actual creature that actually exists, which will die if you kill it. If it existed, a Call Cow or Teleport Cow spell would allow you to steal a cow and slaughter it for its meat. Spells of the Summoning subtype and spells like Astral Projection are more nebulous. A Summon Cow spell would not allow you to steal a real cow or give you a corpse you can eat - when your summoned cow was killed, it would simply vanish.
Depends on the exact spell and its flavour. Ultimately it’s up to player and DM interpretation but that’s how I picture it : the Wizard/Sorcerer spell “Summon Monster X” temporarily draws monsters from the plane they live in, basically ripping open a rift in reality and yanking them through it, then putting magical fetters on it to compel it to help if need be. When the spell ends, the monster pops back out of existence in a puff of smoke. Some monsters lend themselves better to this idea than others - summoning angels, daemons or the spirits of longdead warriors for example makes perfect fantasy sense. Summoning half a tribe of goblins, on the other hand ? Eh :).
The Druid spell “Summon Nature’s Ally” on the other hand I figure is more like a beacon for any beastie nearby to drop what they’re doing, come and help (or, in the case of elementals, either drawing one from the plane of that element, or maybe more of a *Shadowrun *kinda thing where you wake up on that was lying dormant in the local environment). It requires a bit more suspension of disbelief when you’re using it to summon an ankylosaurus, but whatever :). In that case, I reckon the animal helps willingly as it recognizes the Druid as a member of its pack/herd/family. When the spell ends, the animal just fucks off back to where it came from.
In either case, if the summon is killed then it vanishes from play so you can’t use either spell for a quick dinner for instance. No reason the summon wouldn’t remember being summoned if it’s sentient, and some are hostile to the summoner (e.g. in the Baldur’s Gate games, elementals summoned by a Druid are always friendly, but a Wizard summoning one spends some time trying to enslave it. If the Wizard fails, the elemental goes apeshit and attacks everybody, Wizard first. There was also the Gate spell which opened a door to the Hells, and demons pour through. Unless your party is protected from Evil, they don’t mind ripping you to shreds along with your enemy.)
Killing the cow breaks the spell. But would the summoned cow still be dead when it returned to where it came from?
As I said “simply vanished” may cover the event from the magic user’s point of view. But dead or alive matters a lot to the cow.
Let’s say I’m being pursued by a opponent who’s on horseback. I don’t want to confront the guy because he’s more powerful than me. So I cast a summon horse spell. His horse appears before me (probably causing my opponent some difficulty). I put an arrow into the horse and kill it. My summoning spell is broken and the horse returns to my opponent. But my opponent is now on foot because I killed his horse.
Or what happens if I’m fighting an opponent and I summon a wolf to assist me. But unbeknownst to me, the closest wolf happens to be the one my opponent raised from a cub. It appears and immediately attacks me in order to assist its master.
Or my opponent knows I like casting a spell to summon a tiger. So he arranges to have a litter of week old tiger cubs hidden in the next room. I cast my spell and I’ve wasted a spell unleashing the cuteness instead of the fury.
The Gate spell also allowed you to bring into your plane a specific creature you could specifically identify. You could gate anything that you know existed. Whereas summons were nebulous things, gated creatures were full incarnations. And if that gated creature died, well, that’s it. It died. So in the case of gate, you could gate in an animal to eat if you wanted. Of course, you’d have to have a specific one in mind. And any creature that didn’t want to want to go would get a save to negate.
Of course, no one is going to use a 9th level spell for acquiring a single creature worth of provisions. (Hydra head jokes notwithstanding.)
According to the current (5th) edition, conjured animals are actually fey spirits summoned from another dimension that are given animal form upon arrival. If they die, they presumable return to their home plane.
Summoned creatures obey you, and are what you want. Teleported or Gated creatures, not always so. (It would be fun to summon a wolf your opponent raised as a cub and have it attack them. Well, as long as you are evil.)
As shown above though, it seems 5th ed fixed this possiblity with the fey spirits. If you’re in a different edition I would assume it’s up to the DM.
There’s no provision that says you get the closest version of the animal. Wizards and clerics anyway get celestial or fiendish versions of the animal, so they’re from another plane. Even druids, when they summon, may be getting a natural version of the animal from some other plane of existence.
Summon spells used to be abusable by summoning lantern archons that could teleport stuff; you could use them as messengers and traveling merchants par excellence (set up a deal with a merchant to send your swag via lantern archon, and the next day send another one to pick up payment, with the understanding that anyone powerful enough to use lantern archons for gophers isn’t to be crossed). Later editions, maybe Pathfinder, ruled that summoned creatures can’t use teleport effects, ruining the fun.