Designing a Magic System - Part Eight (Fireballs and Magic Missiles)

(You'll probably want to read parts one, two, three, four, five, six and seven before starting this).

If elemental damage is a problematic cliche for how to deliver damage in a magic system, then it is a couple of other problematic cliches, magic missile and fireball, that point to a smarter way of implementing differing damage types. Magic missile is a Dungeons & Dragons trope: a low level spell which creates an uninterceptable sorcerous arrow of energy that seeks out a target in line of sight and hits it - with only very limited ways of the target preventing the attack. They may as well have called it 'Directly Deduct Hitpoints' - and it appears in the latest 4th edition, the designers have succumbed to allowing mages to do this directly for free on a round by round basis.

Similarly Fireball is problematic because its naive implementation: filling a 30' radius volume with flame for any point within line of sight - creates all sorts of issues when interacting with that other cliche, the 10' x 10' corridor, as the volume expands to fill roughly 110 of those corridor grids with fire. The result is a convenient exfoliation of the average size dungeon level (woe betide the designer who has built their dungeon with more realistic size corridors).

Angband's implementation of these is just as problematic, but for different reasons. The Angband magic missile is classed as a bolt spell, which means it hits the first monster when projected from the caster, with the projection moving either cardinally or diagonally through grids to best trace a path from the caster to the intended target. While this avoids the automatically hit anything issue of the Dungeons & Dragons MM, Angband has replaced this with a ridiculous damage to mana ratio, which is not matched by any other spell, along with the fact that magic missile damage is pure and therefore not susceptible to the same problems as elemental magic. As a consequence, magic missile is a reliable workhorse, up to and including the process of killing Morgoth through a magnified death by a thousand cuts. With the spell macroed to the tab key, it is often a process of merely tabbing through encountered monsters without much thought involved, and blinking away should one make melee distance - leading to Angband's not infrequent death by boredom.

I have no issues with keeping a spell useful throughout its life, but I do have problems with the first spell a mage learns being used to kill the end game boss. Although the irony is palpable, this does limit the effectiveness of the mechanic of learning other spells.

Fireball on the other hand is problematic because it remains effectively a line of sight spell, and therefore becomes a game of pick the target I want to inflict the most damage on on a round by round basis. There is the issue that fireball can destroy items on the ground, but this is often an advantage in the hunt for the artifact subgame, as artifacts will remain undamaged while other less useful items burn. Angband doesn't allow fireball volume to be displaced like it does in D&D, so fireball only affects targets within 30' radius - but the one target it doesn't affect at all would at least make the spell more interesting if it did. That's right: in Angband, the caster is immune - rendering it consequence free to use at any range.

At least fireball uses elemental damage, which makes it a less than automatic choice. (Priests get a pure damage ball spell with the same lack of disadvantages that becomes the magic missile workhorse of the priest world - however it is hampered by a much less effective damage to mana ratio.) But as is often the case with computer programmers doubling up as game designers, the temptation to re-use an existing algorithm is too great, so the until recently, almost all other mage spells were an elemental ball of another flavour, which leads to the problems with elemental magic that I highlighted in part seven. (To reiterate: being able to cycle through the same spell in different elemental flavours makes elemental magic less interesting).

So how can these spells be improved in Angband. What would make magic missile a less than automatic choice for starting the game? How can fire/acid/cold/lightning/orangejuice ball be made more interesting? Luckily, I'm able to point to variants: in particular Sangband and Oangband, where the designers have taken a long hard look at the Angband spell systems and redesigned them.

Firstly, magic missile would not be an automatic choice, if there were other viable starting choices and a less overwhelming damage to mana ratio. At a cost of one mana, it is too hard to design other attack spells: by doubling the cost to two, and boosting the starting mage's mana to compensate, the game designer gets more flexibility to create spells that have a cost of three, four or five mana. As for the viability of other starting choices, adding spells that inflict elemental damage, which has the drawback of not damaging every creature that the mage encounters, at the benefit of causing more damage than magic missile, would give the starting mage a different range of options, with clearly defined benefits and drawbacks.

But by adding flame missile, ice missile and so on, we just end up in the same problematic elemental position as fireball: it becomes simple for the low level mage to pick the right flavour once they know the particular elemental vulnerability for a creature. In fact, the problem is worse, because we've just boosted the overall damage output in order to make these spells attractive compared to magic missile. We need to increase the risk of using these spells at the same time as we provide increased damage: ideally we would like to increase the cost of switching from one elemental type to another.

Sangband has one mechanic that does this, which is a weather system for Druidic magic. Within the weather system, there are three different sliders (still air to windy, hot to cold, wet to dry), which vary randomly and can be controlled by a number of weather spells. Each slider increases the effectiveness of one elemental attack while reducing another: in hot weather, fire becomes more effective while cold is not. This makes a druid have to decide whether or not the weather is right to fight a particular monster, and a combination of monsters and weather factors make make a particular scenario especially difficult: there is no ideal time to use cold and fire attacks together. (It would be even more interesting to make the spells themselves affect the weather - so repeatedly using fire would heat the room up, making it harder to fight monsters with cold at the same time).

But the weather is an independent variable which is not necessarily intuitive (can you guess what weather condition boosts acid spells, for instance?). And there is a much more direct and easily understood parameter that we have not considered for damage spells so far. The spell's shape. I've discussed two spells with very different shapes: magic missiles - used against one target, a project which hits the first monster in a direction; and fireballs - affects all targets in a set radius, point and shoot.

And that's the second, obvious recommendation: fireball needs a clearly understood drawback. Which is why in Unangband, I implemented friendly fire - or more specifically self-harming fire. I've hinted earlier that is what it may need: I'll stress it here. If you use a fireball, or for that matter any area of effect spell, too close, you should get damaged as well. The convention comes from grenades in first person shooters, which are the most easily understood, but it is one that can readily be applied to magic attacks. And it is the clearest way to encourage fireball to only be used at a distance - not up close.

I'll suggest an exception, which is spells with a radius which is always centred on yourself. And you may immediately intuit that there's another shape available: combine magic missile and fireball to have radius affecting spells, which apply to the first target they hit. Call them minor fireballs, which is the convention I adopted in Unangband.

And I'm sure you can come up with a library of other shapes. That's what we'll be looking at in part nine: how to design different spell shapes, what is interesting, what is effective, and how to balance different shapes against each other.

And that is part of the secret of designing a magic system: not only must you vary the element the spell attacks with, you must vary the shape. That way, to swap from cold to fire to lightning, you must also swap from any range to far away to close up. And the strength of roguelikes is that this positional system is a fundamental part of the game, something more complex than the Final Fantasies and Bard's Tales of the world - even, when you include tunnelling and other terrain deformation, more complex that Baldur's Gate and Planescape: Torment, the great RPGs of yore, and the major brand FPSes of today.

More to come in part nine. And I'll be confessing the other secret, to my shame, of designing a great magic system in parts ten and eleven.