What is the penalty for not taking the sign from the rubber?

There is no penalty associated with taking signs off of the rubber. The penalty talks about what to do when an Illegal Pitch occurs. The reason for this rule is to prevent a quick pitch. It's purpose is to require the pitcher to do something between stepping on the rubber and delivering a pitch.

Tony

Actually, NFHS rules do state that the pitcher must take his sign from the catcher while on the pitchers plate. With runners on base the penalty is a balk. With no runners it is a ball

NFHS rule 6 article 1 section 1

NCAA rules are a bit different it is only a ball on the batter in NCAA...only OBR does not have a penalty associated with the act. It is considered a "dont do that" in pro rules.

Unless he quick pitches, how do you know if he doesn't get another sign after engaging? The rule only says he shall take signs from the rubber, but it does not say he can't take an initial sign from off of it.

Now you are speaking about application......I quoted the rule...Have I ever balked a pitcher for taking signs off the rubber?.....not in 20 years....I have more items on my checklist in the traditional 2 man system to cover pitch to pitch to discern exactly if he took the sign pre/post or even who is passing the sign...

There are enough legitimate balks to worry about than wasting time on every technical balk.....

If you know all the balks, you could call one on all pitchers every game.....and we would have 4 hour games and coaches after our hides....

That being said there is a rule against it and its quoted above.