The magic system in Dawn of Magic is derived from the standard rules in GURPS Magic, but is modified extensively to use aspects of the ritual magic system presented in GURPS Spirits and Voodoo.

• You still need mana to cast spells - no mana, no magic.
• You must concentrate for a period equal to the "Time to cast" for the spell (1 second if not otherwise specified), as always.
• Distraction still requires a Will roll to avoid losing the spell, and injury still gives a penalty to cast the spell.
• Fatigue costs are unchanged.
• The -1 per yard range modifier remains in effect for most spells. Long distance penalties are still used for spells that call for them.
• Success rolls work the same way - i.e., the fatigue cost is 0 on a critical success, while a critical failure can summon demons, etc.
• Resistance rolls work the same way.
• Spell duration and maintenance (and maintenance cost) are unchanged.

Nevertheless, there are a few significant differences, as outlined below.

High skill has no effect whatsoever on casting time or cost to cast. In other words, no matter how skilled you are, you must always concentrate for the listed "Time to cast" and pay the listed "Cost." This makes magic challenging to use in combat. It also makes it impossible to maintain defensive spells for free. This is just how magic works in Dawn of Magic! On the other hand, actually succeeding at magic use becomes a lot easier with the next few rules . . .

All magical Paths (see below) will name one or more complementary skills. These are skills that can be used before casting a spell in order to obtain a skill bonus. Complementary skills may be mental or physical, and of any difficulty, but they always have a clear connection to the Path in question. All complementary skills work the same way:

1. Declare that you are using your complementary skill before you cast your spell.
2. Roll for the amount of preparation time required to get a bonus to your spell. This will vary by Path and skill. (Note that magic is fickle - you might need 1 second to get a bonus this time, 5 seconds the next time!)
3. Spend this amount of time using your skill. In combat, this will usually require a series of Concentrate maneuvers for mental skills, a series of physical maneuvers (e.g., Wait, Move, or even Attack) for physical skills. A few skills will require Long Actions, or simply be impractical in combat.
4. At the end of this preparation period, but before you start to concentrate on your spell, roll against your complementary skill. For every two points by which you make your roll, you get +1 to your next spell roll (minimum bonus is +1).

Contrary to the GURPS Magic rules, you cannot "burn" hit points instead of fatigue points to power magic. However, you can spend hit points to facilitate magic use. To do so, you must intentionally wound yourself - cut yourself with a knife, thrust your hand into open flame, flagellate yourself with a lash, etc. - and offer up your blood as a sacrifice. This takes one second (and an Attack maneuver, if you choose to do this in combat). Your sacrifice will buy you +1 to the next spell you cast per 2 hit points of self-inflicted injury. Unlike combat injury, these voluntary wounds do not give you penalties to cast your spell!

Note: This rule can result in amazing bonuses. For instance, you could fall on your sword, impale yourself for 20 points of damage, and claim +10 to skill. However, remember that Magical healing is rare in this setting - 20 points of damage might kill you, and even if it doesn't, you will be out of commission for a long time!

There is no Staff spell in Dawn of Magic. If a spell requires a touch, then you must use your hand. Wizards will sometimes use wands in conjunction with their complementary skills, but these artifacts have no intrinsic power.

On the other hand, certain powerful artifacts will give a bonus to magic use - usually with a specific spell of a given Path (but not for the same spell learned via a different Path), occasionally with all spells of a particular Path, and very rarely with all magic. Such an item will function for any wizard fortunate enough to possess it. The wizard must actually have the artifact in hand (requires a Ready maneuver if unready) to claim the bonus, and may claim only one such bonus per casting, regardless of how many artifacts he possesses.

The bonuses for using complementary skills, sacrificing hit points, and wielding magical artifacts are cumulative.

Example: A wizard with skill 8 makes his complementary skill roll by 6 (+3), sacrifices 8 hit points (+4), and wields a magical fetish that gives +3 to skill. His total bonus is +10, for an effective skill of 18.

Groups of wizards may cast magic ceremonially. As in GURPS Magic, this requires ten times the usual casting time and allows the wizards to share the fatigue cost as they see fit. However, the wizards cannot trade energy for skill. Instead, divide all skill penalties by the number of participating wizards (round up) and apply the reduced penalty to the highest skill in the group to determine effective skill.

Example: Three wizards wish to divine information about a subject in a neighboring kingdom, 100 miles away. This would normally give -6 to skill. If they each have skill 15, then they would individually have a 9 or less chance of success. By casting the spell ceremonially, the -6 penalty is divided three ways. This gives only -2 to skill, and a 13 or less chance of success!

To claim bonuses for complementary skill use or sacrificing hit points, all participating wizards must use the complementary skill or sacrifice hit points. Only the lowest bonus of each kind is applied to the final spell roll. Magical artifacts will aid ceremonial magic, but only if wielded by the leader of the ritual. As with individual spell casting, only one artifact bonus may be claimed per spell.

Magic skills in Dawn of Magic are learned quite differently from the spells of GURPS Magic. The rules follow more closely the ritual magic system in GURPS Spirits and Voodoo.

Thaumatology is a M/VH skill that represents the professional knowledge of a wizard. Thaumatology must be studied; it has no default in Dawn of Magic. Since your skill with other magical skills cannot exceed your Thaumatology skill level, it is impossible to work magic without at least a modest level of Thaumatology.

Magery adds to IQ for the purpose of learning Thaumatology skill. Those without Magery learn Thaumatology at -3, but Magery is not a prerequisite. A sufficiently learned scholar could, in theory, become an accomplished wizard! Regardless of IQ and Magery, Thaumatology skill cannot exceed 20. Roll against Thaumatology skill to determine whether an item is magical, to identify the likely capabilities of a new Path upon encountering it for the first time, and to answer general questions about magic and magic use.

Paths are specific lines of magical thinking. A Path can correspond to an abstract concept (e.g., "dreams" or "warfare"), a GURPS Magic college (e.g., Fire or Mind Control), the teachings of a particular school of magic, the writings on the moldy scrolls of a specific forgotten library, or any number of other things. Some wizards specialize in one Path, while others diversify; each approach has its merits.

Each Path is a separate M/VH skill that defaults to Thaumatology-6, regardless of its breadth, depth, or effectiveness (there are bogus Paths!). You must know that a Path exists to use it by default. At minimum, this means that you must see it in use and succeed at a Thaumatology roll.

Default skill with any Path may not exceed 14, and learned skill with a Path may never exceed Thaumatology skill (which means that Path skill may never exceed 20). The most efficient way to learn many Paths is to raise Thaumatology skill to a high level and then build up Paths from their defaults to that skill.

All spells of a given Path default to that Path skill at some penalty; therefore, it is possible to cast every spell of a given Path once you know the Path skill! However, the default penalties for most spells are substantial, so it is usually a good idea to improve your skill with spells you plan to cast frequently.

You can also roll against Path skill to determine whether you can use a Path to produce a given magical effect (i.e., spell), or to answer specific questions about the history of that Path.

As mentioned above, most Paths have complementary skills associated with them, which can greatly facilitate spell casting. See the individual Path description for these skills (and how they work).

Spells are individual feats of magic. The effects, time to cast, cost, etc. are all exactly as specified in GURPS Magic. Each spell is a separate "skill" that defaults to the governing Path at some penalty - usually -6 or worse - that must be bought up from default level at the cost of 2 points per level.

You must know that a spell exists to use it by default. At minimum, this means that you must see it in use and succeed at a Path roll. However, there are no prerequisites under this system; you can learn an advanced spell, and only that spell, without learning any other spell of that Path. Default skill with any spell may not exceed 14, and learned skill with a spell may never exceed Path skill (which means that spell skill may never exceed 20). The most efficient way to learn many spells is to raise Path skill to a high level, and then default all spells from that skill.

It is important to realize that spells are not uniquely associated with Paths. A spell might "belong to" any number of Paths. For game purposes, spells learned via different paths are considered to be different spells, even if they have the same name and function. Points spent on a spell learned though one Path have no effect on the same spell learned via another Path, and wizards who have learned the same spell through different paths may not assist one another in ceremonial magic.