How did this qualify as a "hard puzzle"?
White simply had no worthwhile response to the first move; no variation in the mating piece!

This is poorly constructed because (Rd8 check) produces mate in 2 also yet it does not solve the puzzle. Totally bias and atrocious that the creator only wants this to be solved one way when there are multiple. fix this.

As a general rule, you have to type a message and click the send button first before you can even start realizing how silly you've just made yourself look... so don't judge/convict those who leave silly comments  

I found this about as difficult as today's easy puzzle. I spent about a minute on each. The easy puzzle has a 81% solve rate currently.

But with a 17% solve rate, this is rightly considered to be "hard".

I don't know if it's the number of stars or the solve rate that qualifies this as a "hard" puzzle. But 15% definitely qualifies.

This seems to be one of those puzzles where you see the idea quickly, or not at all. If the right move doesn't come, you can use up those five guesses in a hurry.

I considered 1...Rd8+ without thinking, noticed Black had two interpositions, and moved on. It was soon clear that one good check would mate the trapped king, but that most of White's pieces were frozen as square guarders.

Next I considered 1...Rh3, threatening discovered check and mate by any of the nine moves of the bishop on g3. Many professional problem composers would have used this as a set-up to force a single bishop move for Black's responses. For instance, after 1...Rh3 2.Re2, Black must play 2...Be5#. If White plays 2.Rh2, then Black must play 2...Bh4#.

The problem with this whole contraption is the reply 2.Rb2+, which can't be countered by any bishop move. Examining the situation again, I realized that 2.Rb2+ simply had to be stopped by Any Means Necessary. The knight on c6 can't do that because it has to guard d4. However, the bishop on g3 isn't actually doing anything, so if it moves to c7 blocking the rook ... bingo!

It's an odd situation where it's actually easy to see the possibility of a discovered check in which the bishop blocks Black's defenses, but not so easy to considermaking the blocking move first.

I didn't dislike the puzzle. I could solve it but spent a little while.

A beautiful puzzle. Thanks.

I am a middle-ranked player and spent quite a while on the puzzle, often following phonybenoni's line of thought. I then got my first attempt wrong, putting the dark bishop on the wrong square.
I admire gasping and others who saw it very quickly, but I don't think that detracts from the fact it is a fine puzzle and I'm not surprised by the 17% solve rate.
Thanks desertfoxxx

Either black's first move must itself be a check, or Black must do something to stop White's threatened check. It's pretty easy to mentally eliminate all checking moves as key moves, leaving only the second option.