This is a compilation of the different ways spell systems can work in games. The emphasis is placed upon video game RPGs, but developers of other types of games may find this article useful as well.

Spell Data

Each spell has several parameters. Most games will use most of these parameters in some way. Some possible parameters are listed below.

Cost

Casting a spell typically has some sort of cost. If it didn't, people would just zap everything in the game and win immediately. Various possible costs are listed below.

Corruption: When the caster uses a spell, he becomes slightly corrupted. Over time, the caster mutates into a demon.

Gold: Casting a spell expends gold. In games using this type of spell cost, "spells" are usually called something else.

Items: Casting a spell expends an item (e.g. elixirs, potions, scrolls). Some items may be usable more than once (e.g. rods, staffs, wands). In some games, casting a spell expends more than one item - in these cases, you assemble a number of items (a.k.a. spell components) and somehow combine them into a spell. This is often used as a supplement to another magical system, but there are some games where the items are the spells.

Maintenance: In addition to the initial effect, the caster must also maintain the effect by spending a percentage of the spell cost during each minute the spell is in effect.

Pollution: Casting spells causes some sort of radiation or evil presence in the area. The more spells are cast (and the more powerful the spells are), the worse it gets. Enemies mutate and become stronger. Harmless people go crazy and attack. Inanimate objects come alive and bite you. Gateways open to hell.

Sacrifice: Evil characters murder other characters to allow them to cast a spell. Alternatively, good characters sacrifice themselves. In most cases the sacrifice is performed when the spell is cast, but a good character might cast a spell to become invulnerable for a time and then die when the spell ends.

One-time Casting: When the character learns a spell, he can cast it once. When a spell is cast, it's forgotten. It is, however, possible to learn the same spell more than once simultaneously. What spells the character knows are chosen by one of the following methods:

• Divine Designation: The character's deity determines what spells the character can cast. The character should have to pray (or something) to regain the ability to cast spells, but the character can't choose what spells she'll gain. The deity decides what spells to offer based upon how faithful the character has been to the deity.
• Memorization: Each morning, the character selects spells from a spell book. The character can then cast that spell during that day.
• Negotiation: The character negotiates with a genie or spirit to gain spells.
• Purchase: Spells are purchased and then used once.
• Quest: A character is issued a specific set of spells to use on a quest. Once used, the spells are lost.

Spell Points: A character has some number of spell points, and each spell costs a certain number of spell points. A character expends spell points every time he casts a spell and can't cast any more spells when he runs out of spells points. Spell points are restored in one (or more) of several ways: a) they regenerate over time, b) they are restored by one-use items, c) they are restored by resting, d) they are restored by going to a special location, e) they are restored by defeating enemies. With a spell point system, you can cast whatever spells you want as many times as you want, so long as you have the spell points required to cast them. Some alternatives:

• Experience Points: The character loses experience points instead of spell points. More commonly, extremely powerful spells cost the caster a level of experience. Weaker spells don't typically cost experience points because the character would never get any stronger.

  Faith: Spellcasters gather "faith" from other creatures. It's either faith in some sort of deity that the caster serves or faith in the caster herself. This faith is then expended to cast spells. There is no maximum to the amount of faith a character can gather.

• Fatigue Points: Fatigue points are just like spell points, but fatigue points can be expended through physical exertion too, not just spellcasting.
• Hit Points: This is another "Spell Points" alternative. Hit Points are expended instead of Spell Points. Clearly, this is dangerous to the caster. One possibility is to have powerful spells that automatically kill the caster when cast. This is best used in games with common raise dead spells or expendable allies.

Level Loss: The caster loses a level. This is generally reserved for games where death is final (i.e. if you die, your character is erased), and, even then, it's only used for getting your characters' fat out of the fryer.

Thirst: In cases where characters "sing" spells, they can get thirsty. To regain their singing voice, they have to drink something. This is appropriate for "bard" characters who cast spells by singing.

Time: The spell takes a certain amount of time to cast. During this time, the caster is unable to do anything else and might be defenseless against enemy attacks. This is typically paired with some other form of spell cost.

Usage Frequency: There's no real cost, but the character can only use the spell once every so many minutes/hours/whatever. Alternatively, the character can use the spell 2 or 3 times per day (which is actually similar to Spell Memorization).

Duration

Spell duration can be determined in a number of ways.

• Instantaneous: The spell happens immediately. There's no duration.
• Maintained: The spell lasts so long as it's maintained by the caster. If the caster is killed or rendered unconcious, the spell terminates.
• Permanent: The spell lasts forever unless it's dispelled somehow.
• Temporary: The spell lasts for some specific amount of time.

Effect

The spell has to do something. Otherwise, what's the point?

The effect could be almost anything. For this reason, the entire World of Spells is dedicated to listing the possible effects of various spells.

Effectiveness

There's only a few ways to determine the effectiveness of a spell:

• Determined by a Statistic - The caster has a statistic that determines how effective the spell is. There may be different statistics for different spells or one statistic for all spells. Some systems just use the level of the caster.
• Determined by the Spell - The effectiveness is entirely determined by the spell. It's usually a range of random values.
• All of the above - Use the above methods combined in some fashion.

Limitations

Some spells have limitations that reduce the cost of the spell but make the spell less effective. Some potential limitations are listed below:

• Casting Requirements: The spell can only be cast when some specific requirement(s) is/are met. For instance, the spell can only be cast at night. Or the spell can only be cast underground. Or the spell can only be used during the full moon. The casting requirement has to be something that actually matters. Requiring "Light" spells to be cast only in the dark wouldn't reduce the cost of the spell because it's stupid to cast a Light spell in broad daylight.
• Chance of Backfire: There's a chance that the spell backfires, causing something bad to happen to the caster. The "something bad" may be that the spell affects an ally instead of an enemy (or vice versa) or something else (e.g. summoning a hostile demon).
• Limitting Effect: The spell causes something bad (from the caster's perspective) to happen in addition to the regular effect. For instance, it could injure the caster's allies. In practice, this causes a harmful spell effect to happen to the caster's allies or a beneficial spell effect to happen to the caster's enemies.
• Limitted Targets: The spell only affects particular kinds of targets. Other targets are unaffected. The class example is any attack spell that only affects certain targets (e.g. earthquakes only affecting non-flying creatures and hurricanes only affecting flying creatures).

Range

For spells that allow the caster to select targets, range is important. The range might increase as the caster becomes more powerful.

• Distance - There's a set maximum distance.
• Infinite - There's no limit.
• Line of Sight - The caster can only select targets she can see. Certain spells and items that allow seeing targets from far away may extend the range of such spells.

Resisting Spells

Typically, a beneficial spell isn't resisted, but hostile spells are. Some ways to resist spells are as follows:

• Magic Resistance - Reduces the hostile effect by a percentage and/or subtracts a certain number from any hostile effect.
• Saving Throw - A character has a % chance of avoiding (or reducing) each particular kind of magic effect. This is essentially a Dodge score for magic. Some games use a number from 1 to 20 instead of a %, but it's the same thing.
• Type Resistance - Like magic resistance, but each different type of magic has a different resistance. The classic example is elemental magic.
• Specific Effect Resistance - Like magic resistance, but each different kind of effect has a different resistance.

Targetting

• All Allies - Affects all the caster's allies.
• All Enemies - Affects all the caster's enemies.
• Area Effect - Affects all targets within an area.
• Caster - Affects the caster.
• Environment - Affects the world around the caster.
• Everyone - Affects everyone involved with the combat.
• Footsteps - Affects the tracks the caster leaves on the ground. An example is causing fire to appear on the tracks, injuring anyone who steps on the tracks.
• Item - Affects an item.
• Nearby Allies - Affects allies who are near the caster.
• Nearby Enemies - Affects enemeis who are near the target.
• One Allied Unit - Affects on allied army unit.
• One Ally - Affects one ally.
• One Enemy - Affects one enemy.
• One Enemy Unit - Affects on enemy army unit.
• One Group - Affects one group (usually of enemies).
• Random - Affects random targets. This is the sort of spell you don't want to cast.
• Several Allies - Select several allies for the spell to affect.
• Several Enemies - Select several enemies for the spell to affect.
• Straight Line - Affects all targets on a straight line. This is typically either a "ball" or "bolt" of hostile magic that can be thrown in a direction.
• Straight Line with Refleciton - Affects all targets on a straight line, but the spell can bounce off of walls and things.

Some spells only affect current kinds of characters (e.g. elementals, living creatures, undead, summoned creatures).

Magic Types

In many games, there are different "branches" of magic. Each branch uses a seperate statistic to determine spell effectiveness and resistance to spells of that branch. Some examples are listed below.

Elemental: The spell branches are air/earth/fire/water. This is one of the more popular divisions. Combination spells can have cool names, such as "Rain" for an air/water spell.

Life/Death: Life magic heals, and death magic kills. There's not much confusion there. But then again, life magic often kills undead creatures, and death magic can often heal the caster by draining life from a target. In the Sword of Truth novels, these are referred to as Additive and Subtractive magic.

Psionics: Psionics is "mind" magic, though it's often considered to be technological in nature. Many games have cool psionic effects, but calling them anything other magic is just for the purpose of giving them a different name.

Wild Magic: What is wild magic? It's the same as regular magic except with more randomness.

One of the main problems with spell branches is that many games have spell branches that have spells that, essentially, differ only in name. If any game developers are reading this, please try to make spells that actually have different effects.

Potpurri

What follows is information that isn't central to the discussion. Most of it could have been included elsewhere in this document, but it would distract the reader from more relevant topics. Hence, it was dumped into this section at the end.

Alternate "Spell" Systems

Some games contain spell systems, but call the spells something else. This is no problem. It really just amounts to changing the names of everything.

In some games, "spells" are actually innate abilities. This usually means that the caster can use them with relatively small costs, but the abilities usually aren't as effective. Sometimes, there's a limit to how often the abilities can be used.

In other games, "spells" are technological effects caused by using high-tech items. In some cases, this can be similar to using innate abilities, but in other cases it's more like a game where you have to use scrolls to cast spells. Of course, the "scrolls" will be called grenades or something.

Combined-Spell Spells

These spells are just combinations of other spells. This allows you to cast a number of spells at once. For instance, an "Enhance" spell could cast the Bless, Haste, and Regenerate spells all at once.

These spells are useful because they allow to cast a whole group of spells at once, freeing you to take other actions.

Multicaster Spells

These spells are cast jointly by multiple casters, each of whom expends part of whatever the spell costs. These spells are typically very powerful.

Multicaster spells are inappropriate for many games. They should only be used in games where characters choose their actions at the same time. One possibility to allow multicaster spells in other games is to allow "linking". Several casters link their magic, effectively transferring it all to one caster. That caster can cast the spells, and the rest of the casters are unable to cast spells. In some games, the secondary casters could be rendedered unconcious.

Randomness

Some spells have random effects. Some spells have a chance of failing. Other spells randomly backfire, affecting the caster (though perhaps with a different effect from the normal spell effect).

In general, the spell's cost is as follows: Cost = P(E1) * C(E1) + P(E2) * C(E2) + ... + P(En) * C(En). Ex represents the xth possible effect of the spell. P(Ex) is the probability of effect Ex occuring. C(Ex) is the cost of effect Ex.

Copyright (C) 2005 Steven Fletcher. All rights reserved.