Guild Wars 2

How is crafting rare and exotic items achieved? Do I need to be of certain level, have certain materials or is it the result of critical success? If it is the result of critical success, what is the percentage of it?

I think the yellow ones start pretty early in tier 2 crafting. Like between 75 and 150 and you need to buy the insignia recipes at your master crafter in one of the tabs for karma.

The orange stuff I think only at level 400(instead of yellow then the yellow previous I think is already high in the 300+ area). But have not craftet that much. Not 100 percent sure at least not about the orange stuff.

The materials you need to make rare and exotic weapons/armor can be bought from your crafting master. (They cost karma)