Warning or Deduction

When should there be a deduction for breaking a rule versus a warning? I’ve had this conversation with a couple friends lately and am wondering how more people would answer this and more importantly want to know the reason why?

I have 2 notes with this question.

1. There is no debate about the skill breaking a rule, both the coach/owner and the event representative are in agreement a rule was broken.
2. The answer would apply equally to your team and your opponent.

Please share your thoughts.