How do you guys decide what kind of effects spells have beside their mechanical function?

For example, in one of my games a player decided to hide and cast Hex on an Ogre to prepare to fight him later. Since he was hiding, the players asked if anything happens from Hex: any sounds, glimmers of light, does the Ogre know he was casted on.

I had no clue, and just houseruled something on the spot. Are there no common depictions of these spells to draw on? How do you handle them?

I figure that spells have no such effects other than, as you say, those directly stemming from their mechanical function, short of those game systems that allow special effects -- for good or ill -- to be bought onto individual spells.

Covert spells like Hex Id expect to have no cues to their effect other than if the target makes their save. Then theyd notice "something" that tips them off that a baneful spell was cast on them. They might not know what the spell was or who cast it. But they at least know something happened.

Caster types though Id expect to be able to glean more info from the attempted attack.

But really depends on what your DM thinks it should be. If they think casting hex covers you in a purple glow then thats what happens. If they think theres no visual cue, but the target knows fail or save, then thats what happens.

Quote from: Omega;833499Covert spells like Hex Id expect to have no cues to their effect other than if the target makes their save. Then theyd notice "something" that tips them off that a baneful spell was cast on them. They might not know what the spell was or who cast it. But they at least know something happened.

Caster types though Id expect to be able to glean more info from the attempted attack.

But really depends on what your DM thinks it should be. If they think casting hex covers you in a purple glow then thats what happens. If they think theres no visual cue, but the target knows fail or save, then thats what happens.

Well I'm the DM in this case. I was wondering what the rest of you guys did for representing spells.

Quote from: mAcular Chaotic;833541Well I'm the DM in this case. I was wondering what the rest of you guys did for representing spells.

My general rules of thumb for 5e are (purely personal preference):

If the spell doesn't have an obvious visual effect from the description, then there is no tell-tale glow or what-have-you in the game.

If the target has to make a saving throw and it's intelligent and alert (in combat, on guard), then it knows it was the target of a spell.

If the caster is hidden, but there are verbal or somatic components, then the caster is no longer hidden.

Quote from: mAcular Chaotic;833541Well I'm the DM in this case. I was wondering what the rest of you guys did for representing spells.

Personally I play it that the covert spells usually do not have any cues other than the save. And only if you make the save. That allows for some subtle NPC screw-overs.

Hex though is physically debilitating and so Id say the target likely knows darn well at least the ability drop.

Example I had some NPC wizards trying to covertly probe the groups wizard for info from a few rooms over. I had the player make the save and had he failed I'd have told him "Apparently nothing." and let him wonder what the heck just happened. If anything.

One thing I used in my own RPG was the idea of personalized effects. The same spell from different casters might have the same mechanical effect. But look different. Like Hold person might manifest as nothing at all, chains holding them in place, a glow, a block of ice, whatever.

A flashy caster might make their curse spells cover the target in an eerie glow, or some mark appears. Another might have it as a ray but no visible after effect, another might have it virtually invisible, and so on

Quote from: mAcular Chaotic;833541Well I'm the DM in this case. I was wondering what the rest of you guys did for representing spells.

As I said, zip, except where a spell has a perceptible physics-based effect; Lightning producing a crack, Current producing its own wake, that sort of thing.  I think slapping visible effects onto spells intended to be stealthy defeats the purpose.

Certain systems have other twists.  A HERO-style "obvious focus" means that anything you try has a visible effect.  The GURPS "Frightening Special Effects" perk allows a spell to have horrifying, perhaps morale-busting visuals: a wizard of my wife's, for instance, has the Entombment spell, which is a high end spell designed to suck the victim underground, to be placed in suspended animation for all eternity if not released.  It's otherwise without any particular SFX, but how she does it with the perk bought on is to have a burning rift visibly open in the earth, from which several spectral, demonic hands rise up to haul the victim down, accompanied by a chorus of agonized screams.

Unless the spell has any bombastic visuals (eg: Lightning bolt) but it has verbal and somatic requirements, I'd have the caster do what all the other characters would: make a Stealth check first. Perhaps allowing a social manipulation check if they can weave it into an interaction.

On a fail I'd just say that the target knows that they got jinxed or where the jinx generally came from. On really, really bad fail I'd say that they'd know exactly WHO tried to jinx them.

Quote from: Omega;833499But really depends on what your DM thinks it should be. If they think casting hex covers you in a purple glow then thats what happens. If they think theres no visual cue, but the target knows fail or save, then thats what happens.

For my game, I gave each 'spell school' a specific color, so any visible spell effects and/or magical auras can be distinguished by color.

For instance, Perception spells are purple, Spritism is ghostly white, Kinesis is orange, etc.

Quote from: Necrozius;833686Unless the spell has any bombastic visuals (eg: Lightning bolt) but it has verbal and somatic requirements, I'd have the caster do what all the other characters would: make a Stealth check first. Perhaps allowing a social manipulation check if they can weave it into an interaction.

On a fail I'd just say that the target knows that they got jinxed or where the jinx generally came from. On really, really bad fail I'd say that they'd know exactly WHO tried to jinx them.

What if the caster successfully hides, but the target makes the spell save? Would you have the target somehow know they got targeted? (If the spell has no visual or auditory effects) Or even if they didn't make the save.

Quote from: mAcular Chaotic;833710What if the caster successfully hides, but the target makes the spell save? Would you have the target somehow know they got targeted? (If the spell has no visual or auditory effects) Or even if they didn't make the save.

For me, if a spell has a save, the target will know "Something" happened regardless if they made the save or not, unless for some reason the spell makes sense they wouldn't know.
For example if you do a charm a person and they don't make the save, they certainly won't know they're charmed for the duration of the spell at the very least.
They might work it out later though.

To me, spells in D&D almost always require freedom of motion (for hand movements, tracing mystical signs in the air, etc.), sound (intoning the barbarous names of invocation, etc), and very occasionally some kind of object or ingredient.  Things like range and line of sight being required or not are obviously variable on a spell-to-spell basis.  

As far as the OP's situation: I would say that depending on the spell, it is clear that the caster would  need to hide somewhere that he could still make the necessary gestures; so he couldn't hide in too cramped or enclosed an area.  He would also need to intone the words (that is to say, they have to be vibrated at a certain frequency, not just spoken) which means that he cannot in most cases do this in a whisper (with very few exceptions, like a message-spell, for example).  Thus, unless he had the benefit of significant range, the monster would have been likely to hear him at the very least.  

As far as effect, whether or not anything is seen or felt immediately when the spell is cast depends largely on the spell in question.  In most cases, I would say that the subject 'feels' something odd, but might not be able to identify what that something is, or that it's due to having been the victim of a spell.