user32185: Escaping a double check
The answer to Is it possible to block a double check? says

Moving the king is the only way to escape a double check. There is no possible other move that will block both checks.

But in the following situation, is it allowed for Black to escape by taking the Rook (placing White in check) and forcing a sacrifice of the Queen? If not, why not?
Black to move. Never mind how it got to this position, it's for illustration.


user31954: A legal way to get into the same kind of situation:


But as others have posted: It is illegal to make a move that places or leaves one's king in check.

user32186: Not allowed, no.
White gives two checks (hence double), and meeting one isn't enough.
After blacks reply Qxe8+, blacks king is still in check which makes Qxe8+ an illegal move.
Black is thus checkmated in your position.

user15223: For this kind of questions, if you have doubts, just play chess with the goal of capturing the enemy king. The first player to capture the enemy king wins. This isn't the official rule, but it's effectively the same in almost all situations I'm aware of (it doesn't work for stalemate).
So after 1...Qxe8+, White wins with 2. Nxa8. It doesn't matter that Black also threatens to capture White's king with 2...Qxe1, since White has already won.

32185: <p>Escaping a double check</p>
<p>The answer to <a href="https://chess.stackexchange.com/questions/25053/is-it-possible-to-block-a-double-check">Is it possible to block a double check?</a> says</p>
<blockquote>
<p>Moving the king is the only way to escape a double check. There is no possible other move that will block both checks.</p>
</blockquote>
<p>But in the following situation, is it allowed for Black to escape by taking the Rook (placing White in check) and forcing a sacrifice of the Queen? If not, why not?</p>
<p>Black to move. Never mind how it got to this position, it's for illustration.</p>
<p><a href="https://i.stack.imgur.com/BsRm7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BsRm7.png" alt="enter image description here" /></a></p>
 31954: <p>A legal way to get into the same kind of situation:</p>
<p><a href="https://i.stack.imgur.com/bOPsd.png" rel="noreferrer"><img src="https://i.stack.imgur.com/bOPsd.png" alt="enter image description here" /></a>
<a href="https://i.stack.imgur.com/a9JTU.png" rel="noreferrer"><img src="https://i.stack.imgur.com/a9JTU.png" alt="enter image description here" /></a></p>
<p>But as others have posted: <a href="https://en.wikipedia.org/wiki/Rules_of_chess#Check" rel="noreferrer">It is illegal to make a move that places or leaves one's king in check.</a></p>
 32186: <p><strong>Not</strong> allowed, no.</p>
<p>White gives two checks (hence double), and meeting one isn't enough.
After blacks reply Qxe8+, blacks king is still in check which makes Qxe8+ an illegal move.</p>
<p>Black is thus <strong>checkmated</strong> in your position.</p>
 15223: <p>For this kind of questions, if you have doubts, just play chess with the goal of capturing the enemy king. The first player to capture the enemy king wins. This isn't the official rule, but it's effectively the same in almost all situations I'm aware of (it doesn't work for stalemate).</p>
<p>So after 1...Qxe8+, White wins with 2. Nxa8. It doesn't matter that Black also threatens to capture White's king with 2...Qxe1, since White has already won.</p>
