Handwavium does have some rules:
--
Rob Kelk
"Governments have no right to question the loyalty of those who oppose
them. Adversaries remain citizens of the same state, common subjects of
the same sovereign, servants of the same law."
- Michael Ignatieff, addressing Stanford University in 2012
- It dampens explosive effects to the point where they are not dangerous (the "Slapstick Effect").
- It reacts differently depending the user.
- Once an effect has been established, the person who established that effect can reproduce it.
- It reacts well to a strong will, or to repeated ritual.
--
Rob Kelk
"Governments have no right to question the loyalty of those who oppose
them. Adversaries remain citizens of the same state, common subjects of
the same sovereign, servants of the same law."
- Michael Ignatieff, addressing Stanford University in 2012