I originally created a thread along similar lines, but it was more specific to England's Magna Carta and Charter of Liberties, which I think threw people off to what I was getting at. But, the idea as a generic mechanism in CK2 does sound quite appealing that could very well apply to all kingdoms in Europe.
In short, the noble vassals under you don't want you to have supreme and absolute power over them, so they make you sign a charter, which would also alter the way you play the game, at least in terms of what you can no longer do - which represents the loss of absolute power. On the bright side, your vassals may be more accepting of you if you do sign it (relations boost). This could also be the cause of some revolts under you as well.
You are playing as the King of Yourlands, and your nobles really dislike you because you keep interfering with their business. So they press you to sign a charter (ie, Charter of Liberties). In gameplay terms, you may lose the ability to organize marriages, aside from your own kin (ie, you can no longer arrange marriages for your court members - only blood kin). You may lose tax revenue because they make you agree to a tax cap. The list can go on, but I think you get the idea. These shouldn't be gamebreaking, but they should hamper the king's power a bit.
In short, the noble vassals under you don't want you to have supreme and absolute power over them, so they make you sign a charter, which would also alter the way you play the game, at least in terms of what you can no longer do - which represents the loss of absolute power. On the bright side, your vassals may be more accepting of you if you do sign it (relations boost). This could also be the cause of some revolts under you as well.
You are playing as the King of Yourlands, and your nobles really dislike you because you keep interfering with their business. So they press you to sign a charter (ie, Charter of Liberties). In gameplay terms, you may lose the ability to organize marriages, aside from your own kin (ie, you can no longer arrange marriages for your court members - only blood kin). You may lose tax revenue because they make you agree to a tax cap. The list can go on, but I think you get the idea. These shouldn't be gamebreaking, but they should hamper the king's power a bit.