Ok, my idea is to make different traits based on star signs. Every star sign like Capricorn, Aries, Libra etc. would have different bonuses linked to them. These would be traits so you can select one at startup, BUT you can only have ONE starsign. So, any idea on how to script a trait that only allows you to pick one from a group? What conditions should I use? I could do it with an item, like an amulet that you get in game (you could only get one amulet depending on your choice)

Of course the same kind of system could be used on different kinds of traits, like personality types etc. You can only have one from a select group. So, any ideas on how to do this?