In my opinion, truename magic is a good literary device, but does not play well in a game.
The question in truename magic is "how do you discover someone's truename?" If it's too easy, then a lot of the fun and uniqueness of that style goes away. If it's too difficult, then it may as well not exist.
As well, giving out your truename seems to be the height of foolishness. Why would you ever give someone a chance to wield powerful magic against you?
I think truename magic would work best if you had a reason or mechanism for passing out truenames to other people. Some ideas:
1. A ritual performed by people who know each other's truenames is far more powerful than one without. So trusting someone with your truename can lead to more power if they are trustworthy.
2. Knowing someone's truename leaves you just as open to an attack by them as they are to you. I.e. If you know Bob's truename, you can turn him into a frog, but Bob can also turn you into a frog.
3. Your truename is embedded in the spells you cast. Another caster must observe your spells or enchantments in order to divine your truename. More powerful spells make it easier to discover the truename. Masking your truename makes your spells even more difficult to cast.
The question in truename magic is "how do you discover someone's truename?" If it's too easy, then a lot of the fun and uniqueness of that style goes away. If it's too difficult, then it may as well not exist.
As well, giving out your truename seems to be the height of foolishness. Why would you ever give someone a chance to wield powerful magic against you?
I think truename magic would work best if you had a reason or mechanism for passing out truenames to other people. Some ideas:
1. A ritual performed by people who know each other's truenames is far more powerful than one without. So trusting someone with your truename can lead to more power if they are trustworthy.
2. Knowing someone's truename leaves you just as open to an attack by them as they are to you. I.e. If you know Bob's truename, you can turn him into a frog, but Bob can also turn you into a frog.
3. Your truename is embedded in the spells you cast. Another caster must observe your spells or enchantments in order to divine your truename. More powerful spells make it easier to discover the truename. Masking your truename makes your spells even more difficult to cast.