Much of the magical world is defined by the ability to use magic. In practice, however, magic is itself a science, with clear rules on how it operates and what it can do. Given enough training and practice, anyone can use magic, though what they personally are capable of can vary widely.

Rituals
Magic is cast using rituals. At its most basic, a ritual is a set of instruction which, if followed correctly, will manipulate mana into creating a magical effect. Mana is the source of energy for all ritual magic. Mana occurs naturally in most areas, though some areas have higher concentrations than others, and mana can also be stored and transported for later use. Notably, mana is NOT the source of energy for Gifted.

Rituals grow in complexity and time to complete as the desired effect becomes more complicated or stronger. Some rituals can be completed in less than a minute, while others could take hours or multiple spellcasters working together. Theoretically, there is no upper limit to the length or power of a ritual - in practice, such things aren't attempted (see limits, below). In more practical terms, this means that ritual magic is a slow process, and the image of a wizard simply waving his hand and creating major magical effects is a misconception, mostly perpetuated by the existence of wands (see implements, below). While it is true that an accomplished spellcaster can multitask, take shortcuts, or simply use their time more efficiently through long practice, this only reduces the time rituals take to complete, rather than eliminates it entirely. True masters are capable of producing magic with a flick of the wrist or a muttered word - but the effects they can create in this way are limited to basic utility spells and party tricks. Real magic always requires preparation and time.

Implements
Over the course of centuries, many items have been crafted to make the process of using magic easier or more accessible. They come in a variety of forms and a variety of effects. In practice, most magical items are at least a little unique in their own way.

Ritual books and scrolls: A ritual book or scroll is simply a set of instructions for casting one or more spells. While many spellcasters will memorize the process for casting a personal selection of spells, it is impossible to know a spell for everything, so reference books are required. Most are themselves not magical at all, but there do exist some advanced scrolls which will automate some of the casting process for you. These are very rare, and often in the possession of the spellcaster who created them.

Wands: A wand is perhaps the most common type of magical item in existence. Simply put, a wand holds one or more copies of a completed spell. Casting that spell is therefore as simple as waving the wand in whatever activation pattern was implemented at the wand's creation. The casting of spells from wands give many the impression that magic is as simple as that, but wands have many limitations. In order to charge a wand, the ritual for the desired effect must be completed in full - while waving a wand and casting a three hour ritual in an instant is helpful, it still means someone put in those three hours at some point. In addition, wands can hold limited information. A wand with a simple spell may hold many charges, but wands containing more powerful effects may be capable of holding only one charge at a time. Finally, wands cannot hold any ritual which requires more than one spellcaster to perform. The most powerful effects possible are simply beyond them.

Foci: There are a great many types of foci in existence. Staffs, orbs, rods, totems, and the like are the most common, but many more exotic types exist as well. All of them serve a similar purpose: To store or channel mana. While simple spells can be cast anywhere from ambient mana, the most effective ones require a separate mana source, which a focus provides. Many foci serve additional purposes besides - some store spells like wands, while others may enhance, simplify, or augment certain types of magic. They range from simple creations hardly more effective than using the environment, to ancient artifacts of vast power that would be impossible to create today.

Limitations
Theoretically, anything is possible with magic. Or, more precisely, nothing has been proven impossible. However, in practical terms, many effects are well beyond the capabilities of modern spellcasting. In many cases, a theoretical ritual exists, but attempting to actually cast it would be suicide. The simple reason for this is that as time and complexity go up, the likelihood of making an error - and the level of consequence for doing so - rise sharply. An inexperienced spellcaster attempting a ritual too complex for him is likely to lose hold of the energy he is manipulating. When a ritual fails in such a manner, the effect is based on how much mana is being stressed - small rituals will simply dissipate harmlessly, while slightly larger ones will fizzle and may cause damage. The largest, however, will simply explode, and such explosions generally take the caster with them. The most complex theoretical spells could take days of work for a team of experts - and losing a whole team of experts at once is appealing to no one, least of all the experts who are aware of the consequences. Some notable exceptions do occur - for example, the firestorm that destroyed Washington D.C. But these are only attempted in the most egregious of cases.

It is worth touching briefly on the point that catastrophic failure of a ritual can be prevented - but such prevention requires the use of another ritual. Generally this second ritual takes half the time of the ritual you are trying to ward... and can, of course, also catastrophically fail if performed incorrectly. You can then ward against that ritual failing... but the end result of this chain is doubling the casting time of a complex ritual - if you do everything right the first time. A failure would put you back at square one, and on top of that waste the energy you just blew up and all the energy you spent counteracting that explosion. As a result, attempting rituals beyond your ability is simply not practical.