Key Principles of Odd Traps
1. They announce themselves.
2. They give you opportunity and reason to mess with them.
3. Once triggered, they do their job very well.
Key Principles of Odd Monsters
1. They break the rules.
2. They want something.
3. They do things other than fight.
Key Principles of Arcana
1. They do something new.
2. They encourage creative and risky use.
3. They aren't something you'd want to use all the time.