Scholars mate

Wow

The OP explanation is simple and can be effective if Black blunders with Nf6.

The Checkmate the OP is shown above.

The Queen on h4 attacks the undefended e5 pawn so some players will defend it with Nc6 which is perfectly fine move.

Afterward, White plays Bc4 to double attack f7 square which can lead to a checkmate if Black isn’t careful.

This is the Key position for Black.

They can’t let White checkmate them by taking the f7 square.

Black has a few ways to defend, but this thread isn’t about defending. It’s about Black messing up and so a lot of moves can be terrible for Black.

I will show an alternative bad move.

Bishop move doesn’t help with f7 square so Black gets checkmate their too.

I hate this b.s. like what is the point of using this opening or the Roving Queen? It doesn't teach you anything, and leads to weird, games.

At my level (sub 500) you have to contend with this stuff 1 out of every like 2 or 3 games. It's annoying but it's fun when you punish someone for trying to use these trick openings.

You don't need to "know" any of this. The only thing that matters: when your opponent threatens mate-in-1, do something about it. Usually there are several things you can do. Just pay attention to your opponents' moves, and try to spot the simple threats they are making.