Lieutenant is an ability word, which means that it doesn’t do anything. It’s just there to tie together a theme among cards. In fact, you can just cover up the word “Lieutenant” on the card and just read the ability like normal, and it works the same way. The theme among the card is that the creature gets some bonus if you control your commander. So what counts as controlling your commander?
With Lieutenant, you have to have your commander on the battlefield and under your control to get the bonus. It doesn’t count if your commander is on the stack, and does not count if you control someone else’s commander. And “commanderness” is tied to the physical card: no matter what happens to that card, it’s still your commander. That means if your commander is turned face down by something like Ixidron, it still counts as your commander (so your face up Tyrant’s Familiar is still going to get its lieutenant bonus, since you still control your commander).
It becomes more fun if you manage to Mirrorweave everything into your lieutenant: even though your commander looks like your lieutenant, it’s still your commander, so it will even pump itself!
Keep that in mind: all you need to do is control your commander to get the bonus. Even if your commander looks a little funny, he’s still your commander and you’ll still get the bonus.
Today’s Rules Tip written by Nathan Long