Up to two target creatures each get +1/+2 until end of turn. You gain 2 life.
You can cast Tandem Tactics with no targets. When it resolves, you’ll gain 2 life. However, if you cast Tandem Tactics with any targets and all of those targets are illegal as it tries to resolve, it won’t resolve and none of its effects will happen. You won’t gain 2 life in that case.
