Your magic rules will be believed to be the whole of magic

Magic rules, if you have them, work differently from rules for other things. If your rules say that a human character may move 30 ft. on their turn, players will understand this to be an abstraction. That is because we quite familiar with human ambulation. But not so with magic. So if you write that a 5th level magic user can cast a fireball for 30 damage, that will be the whole of it.

Now, you might be OK with this (also see the next point), but if you also want to have magic wonders of old and rituals darker than night, some players might feel a disconnect: How can my character do that? One way to grasp this vast “other magic” is using rules in the way of long-term projects like in Nobilis 3 or the Workshop rules in PbtA. This is the Ritual from Dungeonworld.

When you draw on a place of power to create a magical effect, tell the GM what you’re trying to achieve. Ritual effects are always possible, but the GM will give you one to four of the following conditions:

· It’s going to take days/weeks/months.
· First you must _________  .
· You’ll need help from  _____________  .
· It will require a lot of money
· The best you can do is a lesser version, unreliable and limited
· You and your allies will risk danger from  ____________   .
· You’ll have to disenchant  ______________  to do it.

It’s basically quest generator.

The easiest way to limit magic is to make it specific

If you are familiar with contemporary fantasy literature and “hard magic” in the style of Brandon Sanderson, you are familiar with this one. That is, many RPGs start with the idea that magic can do anything, then limit it with the likes of spell points.

A simpler approach is to make a limited list of things that magic can do. RPGs with this method are 7th Sea and Reign. In Reign you can be a Sunwise Healer. Then you can heal. You can Soul Forger and forge the souls of animals and conficts into swords. You can be a Fire Dancer and, when you shake it, things get hot.

The game doesn’t bother with spell points. It doesn’t have to because individual mages and magic overall cannot do very much in the grand scheme of things. But mages do fill certain specialist positions in society. For example in the Empire (all magic traditions are regional), there are the Smoke Formers. Their ability is to wave a fan and smoke becomes a solid object for the time. More smoke and formers for bigger objects. What could our beloved Empress do with those guys?

Hire them for the army as engineers. It’s much easier to have some smoke formers wave a way, when you need a quick bridge, then actually build one. Also you have no problems with your enemy using it.

If mundanes shall compete with magic, there should be simple countermeasures

Now, using the above approach, mages will occupy certain niches in society. If you instead want to compete mages and mundanes for the same niches, you have to work a bit more. After all, the basic character fantasy of playing a mage is that things are easier than doing them the normal way.

So yes, magic can do it easily. But most of the time someone took the effort to block that magic. And the best ways of doing that is use non-magic means. For example, we might say that magic flight cannot cross water. Suddenly moats are all the rage and you can still have an age of sail.

There are a few stark indicators that a rule in game, although well-intentioned and fitting the game’s theme, is done badly.

1. Large parts of the audience admit they do not understand the rule or misunderstand it without realizing.
2. Most players just ignore the rule.
3. The rule spawns endless discussion on the intarwebz on how it is meant to be used.

This is about the third kind and I’m not talking Hypothetical Observers from Mage: The Ascension. No, let’s talk Alignment for now.

D&D’s alignment is something a set of moral codes with cosmic relevance. Or maybe cosmic forces which require certain behavior to tap. The most well-known version has 3×3 alignments. These are 3.5 writeups for easy reference.

In later editions the role of alignments for downplayed. 5e has them in theory, but they are mechanically relevant no longer. So even the designers thought there were problems.

To make better alignments, or any morality system really, I posit:

1. Since players have to act this part, these rules should be succinct and easy to remember.
2. It would be fun, if players could discuss the exact meanings. To do so, there should be general, abstract rules.
3. Since players should take different roles, each position should have merit. Some conflict is good, but not in a way to make cooperation impossible.
4. The system should have some impetus for certain behavior. Chickening out by choosing a null option should not be in the cards.
5. But it is a bad idea, to punish players for not acting the part, because playing one’s own character as one sees fit, is so very central to role-playing. Thus the carrot is generally better here, if mechanical reinforcement is sought.

The last concept seems to be general consensus nowadays. D&D5 does it even with their new personality traits and Inspiration. Of course, this a system for personal motivations and quirks, not something that makes the character adherent to some philosophical or metaphysical standpoint.

But D&D’s alignments aren’t so hot with the other points either. It is actually hard to say what each alignment is about and therefore harder still to argue about in character. Neutral or Chaotic Neutral are often used as the aforementioned null options.

Now, are there games that do this better? – I’m glad you asked. Nobilis 2nd Edition did. How does it work:

• Each affiliation or code has 3 precepts for easy memorisation.
• When you struggle because, you try to uphold your code, you gain Miracle points (carrot).
• None of the codes is called Good or Evil. Heaven / Hell and Light / Dark might indicate some flavor of the kind, but none of the codes is actually “nice”.
• The precepts are made so that the Affiliation’s interests are not irreconcilable. For example Light wants to safe humanity, while Dark wants to corrupt individual humans.
• If you do not like any of those codes for your character, you may write your own, making you one of the True Gods of Earth.

Using this as inspiration, I scribbled down six Heroic Alignments. This is certainly still rough, but may serve as an example.

Shield

• Everyone has their strength. 
• The strong must protect the weak.
• If the monsters are too powerful, their rampage must be mitigated. 

Spear

• Aspire excellence in all things. 
• Help others do likewise.
• There is no excuse to stay weak.

Book

• Laws should be codified, known and respected
• The words of legitimate leaders are akin to law. 
• Charity is dubious and prone to corruption.

Chalice

• Sharing is the highest virtue.
• Prefer consensus over vote; everyone must be heard.
• Tyranny must be resisted in all forms.

Sword

• The laws of men are fallible, justice is eternal.
• Justice commands that debts be paid.
• Let no criminal escape.

Cap

• Do no harm, lest you will be harmed.
• Feel free to help that along, if fate needs a hand.
• Traditions should be tested. 

Incidentally, the 3 Precepts pattern was used for the gods in the D&D’s 4e Players’ Handbook. So if you want something directly from WotC you can use those (click the individual dieties to see their precepts).