Does using Ambush from the plains to put a character into play from your hand makes you able to use an "after you play X from your hand" response?
In short does using Ambush from the plains the same as "playing" a character from your hand?
Ambush from the plains question.
No. You are putting the card into play, which is not the same as playing a card from your hand. You can find the specific wording differences in the FAQ.