I am starting this article so we can as a collective define magic in its many facets. I will present all sides fairly and would love for a discussion on the merit of each to happen. Please be respectful and if using a source please cite it so we may all benefit from the information itself.

Quotes about Magic

Magic is "The Science and Art of causing Change to occur in conformity with Will." -Aleister Crowley

Tips for Magic in your Roleplays

Depends on what you want out of magic. There are several different ways you can do magic, all perfectly valid. I find the most successful kind I use tends to be a supernatural force that is constrained only by the physical limitations of the user. In general, though...

#1: The more powerful the spell, the longer it should take to gather the energy to complete the spell. Compare to, say, a download. If you're downloading a small movie clip on YouTube, it should be done pretty quickly. If you're trying to download an entire movie however, that will take a little longer. Physical curtails. Whether this is a hard limit in which a character cannot cast spells beyond X level of power or a soft limit in which characters begin to hurt themselves casting beyond a certain point or level of power, there needs to be something that stops mages from downloading meteor.exe and wiping out the entire enemy fortress. Single handed.

A detection method for mages. This can vary from mages being able to sense other mages to some physical change in wielders of magic that makes them visible to something else. This prevents "gods in robes" from forming, which are characters whom are potent magicians and can plainly and obviously defeat any character they come across simply by being able to hide their talent. This would be like if a professional swordsman could hide his two handed claymore and then just have it magically appear in his hands.

Outright banning certain forms of magic, maybe because it's outside of human physical capacity, maybe because magic simply doesn't cover it, but things like chronomancy--power over time--and unlimited no restrictions shapeshifting, or mind control at any range, or stuff like this, is absolutely impossible to counter or balance without rigging even more broken circumstances to fight it with, which upsets everyone involved and puts into question the true power of magic in your universe.

Magic is quite literally anything outside of what is normally impossible made possible. Like summoning fire and not burning yourself as a result.

Fair points raised by Brovo and something I agree with. Mythicscribes.com raised a similar point about characters. Magic is out of the ordinary and in my opinion can be quite fun to play with, but in the last paragraph the point about counter balances are raised. Magic without something to counter it is boring and the character boring to read about. What I love about magic as an avid medieval fantasy roleplayer is what it can add to the story. There are even several stories that involve magic, much like technology causing Apocalypse type events due to the destructive nature that comes with overuse. This article, this guide is not intended to tell you, the reader, what to do in your roleplay. Instead I would like this to be a place that provides food for thought.

Next time your character uses magic consider what it takes for them to conjure that fireball. Do they require a specific mental state such as rage? Do they require focus in order to not lose control? Does it drain part of their magical or life force in doing so? Why does the situation require magic in itself to solve?

The Effects of Magic on Your Roleplay

Stuff like magic needs to be very well watched.

The second players started getting force sensitive the story kept moving, but the power level went through the roof and backtracking to a lower power level just made us feel robbed. So by the time our adventure was finished and we 'saved the galaxy' there wasn't much else to do, so our ice cream melted and we all eventually drifted off, some of the Guild and others simply stopping roleplaying period.

Stuff like that is something that really needs to be looked out for when magic enters, how much? Can you back track without bad effects? Will this cause a power rush that will melt the ice cream you worked so hard to create? There's a lot of charm in lower powered campaigns and roleplay's that a lot of people don't see value in until you've tried it yourself and overcame the challenges in other means, And once magic/the taste of greater power has been introduced, it's almost impossible to shake off.

Brovo has some good guidelines if you decide to bring it in to begin with.
But before you even look at those ask if you even want to take the RP to such a power level, do you want results determined partially by a greater/mystical power that players can control directly? Is this something you think you can been controlled and stable, or something that will cause a forever power ramp?

For those unfamiliar with Star Wars, the force is like magic. An ability that can be manipulated to push users beyond their normal range of abilities, much like magic in any other setting. Magic Magnum in this quote is speaking of the effects that magic can have on your roleplay, which brings up a very good point. It is important to be clear how magic works in your setting and why. What power level can magic users rise to and how? Ideally this should be done in an interest check, the place where the Ad Idem occurs. That is to say "The meeting of the minds." Everyone should be clear on the Who, what, where, why, and how of magic.

More on the GM side of things now. Magic is something of a major theme when introduced to any setting. When considering if you wish magic in your setting it is important to think about the longer term impact of it on the world, but also how the living beings in the setting feel about magic. Are magic users trusted or are they pariahs? Are there associations or groups of magic users, if any? Your players will be asking you a few questions about magic no doubt, so it is important to consider the role of magic in your world.

(Do note this thread is a work in progress and will be updated roughly every few days. I will give credit where it is due and appreciate all contributions to help further quality roleplaying on this site.)

Depends on what you want out of magic. There are several different ways you can do magic, all perfectly valid. I find the most successful kind I use tends to be a supernatural force that is constrained only by the physical limitations of the user. In general, though...

#1: The more powerful the spell, the longer it should take to gather the energy to complete the spell. Compare to, say, a download. If you're downloading a small movie clip on YouTube, it should be done pretty quickly. If you're trying to download an entire movie however, that will take a little longer.

#2: A detection method for mages. This can vary from mages being able to sense other mages to some physical change in wielders of magic that makes them visible to something else. This prevents "gods in robes" from forming, which are characters whom are potent magicians and can plainly and obviously defeat any character they come across simply by being able to hide their talent. This would be like if a professional swordsman could hide his two handed claymore and then just have it magically appear in his hands.

#3: Physical curtails. Whether this is a hard limit in which a character cannot cast spells beyond X level of power or a soft limit in which characters begin to hurt themselves casting beyond a certain point or level of power, there needs to be something that stops mages from downloading meteor.exe and wiping out the entire enemy fortress. Single handed.

#4: Outright banning certain forms of magic, maybe because it's outside of human physical capacity, maybe because magic simply doesn't cover it, but things like chronomancy--power over time--and unlimited no restrictions shapeshifting, or mind control at any range, or stuff like this, is absolutely impossible to counter or balance without rigging even more broken circumstances to fight it with, which upsets everyone involved and puts into question the true power of magic in your universe.

Beyond those four points, there's not much that needs to be said about magic, because magic is quite literally anything outside of what is normally impossible made possible. Like summoning fire and not burning yourself as a result.

Stuff like magic needs to be very well watched.

I once was an admin for a star wars RP site where a dozen of us did a ton of different star wars RP with the same characters, but we organized all RP's in a timeline so in a sense it was one giant RP/adventure that lasted for about 3 years. All of our most memorable moments were when power levels are lower, the force wasn't something seen often and if it was then it was usually the enemy.

The second players started getting force sensitive the story kept moving, but the power level went through the roof and backtracking to a lower power level just made us feel robbed. So by the time our adventure was finished and we 'saved the galaxy' there wasn't much else to do, so our ice cream melted and we all eventually drifted off, some of the Guild and others simply stopping roleplaying period.

Stuff like that is something that really needs to be looked out for when magic enters, how much? Can you back track without bad effects? Will this cause a power rush that will melt the ice cream you worked so hard to create? There's a lot of charm in lower powered campaigns and roleplay's that a lot of people don't see value in until you've tried it yourself and overcame the challenges in other means, And once magic/the taste of greater power has been introduced, it's almost impossible to shake off.

TLDR: Caution. Brovo has some good guidelines if you decide to bring it in to begin with.
But before you even look at those ask if you even want to take the RP to such a power level, do you want results determined partially by a greater/mystical power that players can control directly? Is this something you think you can been controlled and stable, or something that will cause a forever power ramp?

Thank you for your contributions so far everyone. I know it isn't much to look at now, but hopefully we can get our robust guide section back to its former glory.

Maybe it's because I'm such a gigantic book-nerd...but I tend to enjoy the idea of magic that follows certain rules. Since I read a LOT I've come to recognize some key characteristics that make me enjoy magic, I'll be employing these in my RPS.

1. Magic can't spring from nothing, and must have consequences.
This is a fairly common theme among the best authors who use magic. The mage will eventually run out, and their skill as a mage depends not only on their magical knowledge, but on their ability to apply the least amount of power to the greatest effect. In addition, using up all of the currently available magic will have consequences, and dire ones. A mage who drains their stores completely risks unconsciousness, long term reduction of their power-level, long-term health effects (maiming, injuries, loss of magic entirely, ect), and also death.
When magic is unending in it's use I find myself getting bored. Sure, Lord Thus-and-so killed three dragons and an entire orc horde by himself, but if he does it without breaking a sweat and seemingly without any real cost to himself who really cares?

2. People have different skills, talents, strengths, and weaknesses. Mages should to.
I know everyone here is familiar with Mary Sue's and why they're no fun...this is sort of an extension of that. To me, if all mages have the exact same level of power and all that varies is how clever you are...wouldn't a small band of 'good' mages easily be able to wipe out a singular 'bad guy'? Boring.
Some mages should be weak, like lighting a candle once a week levels of power. This makes it just that much more fun to apply your meager power to good effect. Using your intellect to boost what you're capable of. On the flip side, why would it be fun or exciting to be Superman if else was ALSO Superman/woman. It wouldn't. You need balance to make it enjoyable and add another level of realism. Different strengths and weaknesses make playing fun, if everyone can do the super-cool unlocking spell to open the dungeon, and the fire ball spell to kill the ogre, and the hover spell to cross the moat...why did it take 6 of you to get the treasure?

3. Do mages spring from their mother's loins as fully capable Masters?
You need to learn to walk, run, jump, speak, ect. IMO incorporating a learning curve into a magical RP adds a lot more options and excitement. If you join up and immediately start blasting away with your awesome wizard-bolts...how do you move up from that? Again, boring.
Mages should be able to learn tricks from fighting their opponents, to push their own boundaries - magical, mental, physical and otherwise.

4. What greater cost does magic use have?
If you use a system of magic where the power comes from outside of the mage where does it come from? How does that drain effect the surroundings? Can magic backlash like electricity? What does that cause? What does a complete drain on all the magic of an area do? What does letting loose a gigantic storm of power (as in a mage-battle) cause on the surroundings? How do the lowly townspeople feel about you slurping the power out of their crops in order to kill the Evil King Tax-a-lot?
Again, considering these points adds another level of depth and realism to the game.

*shrugs* just my thoughts :) I hope I was clear enough, lol

Arthur C. Clarke's Third Law: "Any sufficiently advanced technology is indistinguishable from magic."

http://en.wikiquote.org/wiki/Arthur_C._Clarke#On_Clarke.27s_Laws

This means that in science fiction, or even just RPs where technological innovation is allowed, you will face the same problems as you do in worlds with magic. Technology can easily reach a level where all else becomes inferior, and everything gets out of control. An obvious example is far-future sci-fi, where if you aren't careful you will come across devices which can do anything, from flawless cloaking devices to devastating hand-held super-weapons to literally impenetrable shields to limitless teleportation to time travel to manipulating the very nature of the Universe itself. And if multiple sides have access to such technologies it can easily spiral out into an arms race.

Even if you're not in the far-future, technology can still progress to a stage where it is magical. Say you have a medieval setting. Some clever guy discovers gunpowder. From there, firearms are a short step, and it doesn't take much extrapolation to create better and better firearms and it won't be long until you have weapons which are centuries ahead of their time and any players who get their hands on them become unstoppable.

The solution to preventing technology from spiralling out of your control is similar to that with magic. Obviously, intense physical strain beyond a point is not applicable in most cases, but there are other ways to limit technology. One is to have clear limits on the technology in your RP. Another is to have advanced technology expensive to operate, or the power/ammo/mineral to run it is rare. Another way is to have highly sophisticated and advanced technology difficult to acquire by PCs.

These methods can be applied directly back to magic. Magic can have clear limits in the RP. Magic can be costly to perform. Magic can require rare consumable items (magic crystals, complicated potions, etc.). Magic which a PC can use could be limited to simpler things.

In short, problems you see in magic can arise with technology too, and can be fixed in much the same ways.

I have a more magic centred addition to this guide.

http://tvtropes.org/pmwiki/pmwiki.php/Main/LinearWarriorsQuadraticWizards

"A quirk some Video Game and Tabletop RPG game systems share is that melee classes are more powerful, versatile or useful at lower levels than casters or magic using classes. However, the trend reverses at higher levels, when the magic users gain a breadth of both versatility and pure power over simplistic hack and slash heroes."

In brief, magic users can easily get much more powerful than they should be. Their increase in power in relation to experience accelerates as they get more experience, as they get not only stronger but also have more powerful and diverse spells at their disposal. This is in contrast to other means of combat, such as melee combatants, where their strength progresses more or less evenly, especially since they don't have the versatility of magic users and face physical limitations. Magic, on the other hand, is there to overcome physical limitations.

On the flip side, early on magic users are typically weaker than warriors as their powers are not useful until they are well-trained. However, early on warriors have the upper hand as it doesn't take much training to bash up your enemies.

A way to counter the disproportionate increase in magical power is to put some kind of limitation on it, such as limited power (often 'mana') or some physical or mental cost of using magic. Care needs to be taken there to avoid nerfing wizards too much, otherwise the scales may tip the other way and they may become effectively useless.