Viva la Vida
A pledge is like a Contract made between two or more people. There are benefits you can receive from it if things go well, and there are punishments for if things go wrong. They can be open or formal in terminology, and bind multiple parties together.
You can swear a pledge on numerous things, for numerous things, and about numerous things. I admit, I’m not the most well-versed in pledges, but they are a doozy, and if you do them right, great things can come to you. Ask your Storyteller if you’re interested, but be warned—they’re a little bit complicated.