Hidden Ninja

Hidden Ninja
SpellBuffCost: 2
Up to two of your units and/or heroes with 4 ATK or less have stealth this turn. (Can sneak past patrollers if that opponent has no detector.)
If either is a Ninja or Ninjutsu hero, draw a card.
WhiteNinjutsu Magic

Card-Specific Rulings
If the unit or hero has more than 4 ATK later that turn, it keeps stealth. — Sirlin
Stealth Rulings
"Sneaking past" means you can ignore patrollers when attacking and attack anything you want. You can also attack the patrollers if you prefer. — Sirlin
When something with stealth attacks an enemy unit or hero, that enemy unit or hero DOES deal its combat damage back as usual. — Sirlin
If an opponent has the Tower add-on and their tower has already used its once-per-turn detect on something, then you attack with something that has stealth, the Tower will not deal its damage to your stealth thing. It would if it's once-per-turn detect hadn't been used, but it can only damage things it can see. — Sirlin