user18029: A decoy or deflection typically lure an opponent's piece away from a square. What is it called when you sacrifice in order to lure/force an opponent to a certain square in order to prevent another piece escaping? 
Here is a bad example that I've made that shows the idea. The reason it's bad is because the lure isn't actually needed since d8 is already attacked by the black rook.
[FEN "3r1rk1/ppp2ppp/8/2b5/4P1RP/5q2/PPQ5/RN2KN2 b - - 0 1"]

1... Rd1+ 2. Qxd1 Qf2#


user10380: In PDB the keyword "Lenkung" in German ("steering" in English) is used for the tactic of White forcing Black to move a unit to a specific square where White wants it to be. "Steering" has wider usage than what the OP seeks. For one thing, this square might or might not be a black king-flight. For another, in some cases the steered unit is Black's king. To narrow a search down to what the OP wants, you could also use PDB's keyword "Remote selfblock".
Here's a case where White does force Black to self-block:
[Title "Manfred Schmidt. Freie Presse (Chemnitz), 15 Jan 1988, no. 2873. Mate in 4"]
[fen "8/p1K4B/k1N5/8/1R6/8/2b5/8 w - - 0 1"]
[StartFlipped "0"]

1. Bg8 Bb3 2. Bc4+ Bxc4 3. Ra4+ Kb5 4. Ra5#

FEN 8/p1K4B/k1N5/8/1R6/8/2b5/8
PDB link

Ra4+ Kb5 2. Ra5 would work, except that Black's bishop guards a4, and Black's king can escape via c4. So White first steers that bishop to c4 where it will block a king-flight.


user15543: As far as I know, the term for a sacrifice that causes a player to block an escape square called a “selfblock,” altough it is a type of selfblock.
For a composed example, here is one that shows the idea. White sacrifices a pawn on  d4 and a rook on e4 and this causes Black to move their pieces to those squares, thus taking away escape squares from the Black king.
[Title "Julio César Infantozzi, Mate In 16 Moves"]
[FEN "R1n2N2/4pk1B/2Q1r2B/2K2b2/Rr1n2P1/1q1P1PP1/4N2b/8 w - - 0 1"]

1. Qe8+ Kxe8 2. Rxc8+ Kf7 3. Bg8+ Kxg8 4. Ng6+ Kh7 5. Rh8+ Kxg6 6. Nf4+ Kf6 7. Rf8+ Ke5 8. Bg7+ Rf6 9. Bxf6+ exf6 10. Re8+ Ne6+ 11. Rxe6+ Qxe6 12. Ng6+ Bxg6  13. f4+ Rxf4 14. gxf4+ Bxf4 15. Re4+ Bxe4 16. d4

You can find more such chess problems here, and there is even a ChessBase article on the subject.
I found a game where this actually occurs, pulled from this chessgames collection.
[Title "Tigran Levonovich Petrosian-Ara Minasian, 66th Armenian Championship, Yerevan Armenia, 3/19/2006"]
[FEN ""]
[startply "56"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. O-O Nxe4 5. Qe2 Ng5 6. Nxg5 Qxg5 7. d4 Qe7 8. dxe5 Nd4 9. Qd3 Qxe5 10. Bd2 Ne6 11. Re1 Qd6 12. Qh3 Be7 13. Bd3 c6 14. Nc3 Qc7 15. f4 g6 16. g4 O-O 17. f5 Ng5 18. Qe3 Bf6 19. Rf1 d5 20. fxg6 d4 21. gxh7+ Kg7 22. Qe1 dxc3 23. Bxc3 Qb6+ 24. Kh1 Bd4 25. Qh4 Ne6 26. Qf6+ Bxf6 27. Bxf6+ Kh6 28. Rf5 Ng7 29. Rh5+ Nxh5 30. g5#

White “sacrifices” their rook to h5 with a check, which in turn causes Black to move their knight there, depriving the king of an escape square, aka a selfblock.

user19877: What you are looking for is called "attraction". That is, you attract a piece to a specific square. One of the most famous types of attraction is seen in this example:
 [FEN "r1b2rk1/pp2pp1p/1qp3p1/4Q3/1n1N4/1P6/PBP2PPP/R4RK1 w - - 0 1"]

 1. Qg7+ Kxg7 2. Nf5+ Kg8 3. Nh6#

Here is a nice link with another example.
This is also exactly a deflection since you deflected the queen away from f2. By the way, 1...Bf2 2. Qxf2 Rd1 also the same.
Here are two examples of what Rewan Demontay described as "self-blocking" below. In the first, a study by Nimzovich, it is what I believe the OP is asking for. The other is another type of self-blocking move, but it is not the opponent that forces it. This is more common in some endgame tactics to draw where one side walls the king in so it will be a stalemate.
 [FEN "5rn1/2N1npk1/R7/4P3/8/4P3/Q7/K6R w - - 0 1"]

 1. Rg6+ $3 fxg6 (1... Nxg6 2. Qxf7+ Rxf7 (2... Kxf7 3. Rh7#) 3. Ne6#) 2. Qf7+ $3 Rxf7 (2... Kxf7 3. Rh7#) 3. Ne6#

Here is the other self-block, but for another reason.
 [FEN "8/r6k/3r3p/5p1K/5P2/p6P/Q7/8 w - - 0 0"]

 1. h4 Rd1 2. Qf7+ Rxf7 {Stalemate}


18029: <p>A decoy or deflection typically lure an opponent's piece <em>away</em> from a square. What is it called when you sacrifice in order to lure/force an opponent <strong><em>to</em></strong> a certain square in order to prevent another piece escaping? </p>

<p>Here is a bad example that I've made that shows the idea. The reason it's bad is because the lure isn't actually needed since d8 is already attacked by the black rook.</p>

<pre><code>[FEN "3r1rk1/ppp2ppp/8/2b5/4P1RP/5q2/PPQ5/RN2KN2 b - - 0 1"]

1... Rd1+ 2. Qxd1 Qf2#
</code></pre>
 10380: <p>In <a href="https://pdb.dieschwalbe.de" rel="nofollow noreferrer">PDB</a> the keyword &quot;Lenkung&quot; in German (&quot;steering&quot; in English) is used for the tactic of White forcing Black to move a unit to a specific square where White wants it to be. &quot;Steering&quot; has wider usage than what the OP seeks. For one thing, this square might or might not be a black king-flight. For another, in some cases the steered unit is Black's king. To narrow a search down to what the OP wants, you could also use PDB's keyword &quot;Remote selfblock&quot;.</p>
<p>Here's a case where White does force Black to self-block:</p>
<pre><code>[Title &quot;Manfred Schmidt. Freie Presse (Chemnitz), 15 Jan 1988, no. 2873. Mate in 4&quot;]
[fen &quot;8/p1K4B/k1N5/8/1R6/8/2b5/8 w - - 0 1&quot;]
[StartFlipped &quot;0&quot;]

1. Bg8 Bb3 2. Bc4+ Bxc4 3. Ra4+ Kb5 4. Ra5#
</code></pre>
<p>FEN 8/p1K4B/k1N5/8/1R6/8/2b5/8</p>
<p><a href="https://pdb.dieschwalbe.de/P1136031" rel="nofollow noreferrer">PDB link</a></p>
<ol>
<li>Ra4+ Kb5 2. Ra5 would work, except that Black's bishop guards a4, and Black's king can escape via c4. So White first steers that bishop to c4 where it will block a king-flight.</li>
</ol>
 15543: <p>As far as I know, the term for a sacrifice that causes a player to block an escape square called a “selfblock,” altough it is a type of selfblock.</p>
<p>For a <a href="https://www.yacpdb.org/#327955" rel="nofollow noreferrer">composed example</a>, here is one that shows the idea. White sacrifices a pawn on  d4 and a rook on e4 and this causes Black to move their pieces to those squares, thus taking away escape squares from the Black king.</p>
<pre><code>[Title &quot;Julio César Infantozzi, Mate In 16 Moves&quot;]
[FEN &quot;R1n2N2/4pk1B/2Q1r2B/2K2b2/Rr1n2P1/1q1P1PP1/4N2b/8 w - - 0 1&quot;]

1. Qe8+ Kxe8 2. Rxc8+ Kf7 3. Bg8+ Kxg8 4. Ng6+ Kh7 5. Rh8+ Kxg6 6. Nf4+ Kf6 7. Rf8+ Ke5 8. Bg7+ Rf6 9. Bxf6+ exf6 10. Re8+ Ne6+ 11. Rxe6+ Qxe6 12. Ng6+ Bxg6  13. f4+ Rxf4 14. gxf4+ Bxf4 15. Re4+ Bxe4 16. d4
</code></pre>
<p>You can find more such chess problems <a href="https://www.yacpdb.org/#search/ODg4ODg4ODgvLy8vLy8vLy8vU2VsZmJsb2NrLCAvLy8xLzEvMS8w/1" rel="nofollow noreferrer">here</a>, and there is even a <a href="https://en.chessbase.com/post/problem-che-the-self-block" rel="nofollow noreferrer">ChessBase article</a> on the subject.</p>
<p>I found a game where this actually occurs, pulled from this <a href="https://www.chessgames.com/perl/chesscollection?cid=1006488" rel="nofollow noreferrer">chessgames collection.</a></p>
<pre><code>[Title &quot;Tigran Levonovich Petrosian-Ara Minasian, 66th Armenian Championship, Yerevan Armenia, 3/19/2006&quot;]
[FEN &quot;&quot;]
[startply &quot;56&quot;]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. O-O Nxe4 5. Qe2 Ng5 6. Nxg5 Qxg5 7. d4 Qe7 8. dxe5 Nd4 9. Qd3 Qxe5 10. Bd2 Ne6 11. Re1 Qd6 12. Qh3 Be7 13. Bd3 c6 14. Nc3 Qc7 15. f4 g6 16. g4 O-O 17. f5 Ng5 18. Qe3 Bf6 19. Rf1 d5 20. fxg6 d4 21. gxh7+ Kg7 22. Qe1 dxc3 23. Bxc3 Qb6+ 24. Kh1 Bd4 25. Qh4 Ne6 26. Qf6+ Bxf6 27. Bxf6+ Kh6 28. Rf5 Ng7 29. Rh5+ Nxh5 30. g5#
</code></pre>
<p>White “sacrifices” their rook to h5 with a check, which in turn causes Black to move their knight there, depriving the king of an escape square, aka a selfblock.</p>
 19877: <p>What you are looking for is called "attraction". That is, you attract a piece to a specific square. One of the most famous types of attraction is seen in this example:</p>

<pre><code> [FEN "r1b2rk1/pp2pp1p/1qp3p1/4Q3/1n1N4/1P6/PBP2PPP/R4RK1 w - - 0 1"]

 1. Qg7+ Kxg7 2. Nf5+ Kg8 3. Nh6#
</code></pre>

<p><a href="https://chesstempo.com/tactical-motifs.html#attraction" rel="noreferrer">Here is a nice link with another example.</a></p>

<p>This is also exactly a deflection since you deflected the queen away from f2. By the way, 1...Bf2 2. Qxf2 Rd1 also the same.</p>

<p>Here are two examples of what Rewan Demontay described as "self-blocking" below. In the first, a study by Nimzovich, it is what I believe the OP is asking for. The other is another type of self-blocking move, but it is not the opponent that forces it. This is more common in some endgame tactics to draw where one side walls the king in so it will be a stalemate.</p>

<pre><code> [FEN "5rn1/2N1npk1/R7/4P3/8/4P3/Q7/K6R w - - 0 1"]

 1. Rg6+ $3 fxg6 (1... Nxg6 2. Qxf7+ Rxf7 (2... Kxf7 3. Rh7#) 3. Ne6#) 2. Qf7+ $3 Rxf7 (2... Kxf7 3. Rh7#) 3. Ne6#
</code></pre>

<p>Here is the other self-block, but for another reason.</p>

<pre><code> [FEN "8/r6k/3r3p/5p1K/5P2/p6P/Q7/8 w - - 0 0"]

 1. h4 Rd1 2. Qf7+ Rxf7 {Stalemate}
</code></pre>
