Zada’s ability will trigger if you cast a spell that only targets Zada. Zada’s ability will not trigger if Zada and anything else is targeted; Zada has to be the only target for the spell in order for it to trigger and for you to get copies. So let’s look at a card like Tandem Tactics. The Tactics can be cast with 0, 1, or 2 targets. If you cast the Tactics with 0 targets, well, Zada won’t trigger since the Tactics has no targets. If you cast it with two targets (one targeting Zada and the other targeting another creature), then Zada will not trigger either. Although Zada is being targeted by the Tactics, Zada is not the only target for the spell. Since Zada is not the only target for the Tactics, Zada will not trigger. However, if you cast the Tactics with just one target, and that target is Zada, Zada will trigger. Zada will make a copy of the Tactics for each other creature you control. You don’t get to change the number of targets for the copies, so you can’t have the copies have two targets: they’ll have one target just like the original. Even better, each copy is their own spell, so you’ll effectively gain 2 life for each creature you control (and all of your creatures will get +1/+2 until end of turn).
Today’s Rules Tip written by Nathan Long