user4050: There are some opening lines where grabbing material is very dangerous – another question of mine serves as a good example.
However, are there some trick lines where the only reasonable choice is to grab extra material leading to a game playable for the player offering material? At first some gambits come to mind where one has to take a pawn first, but rather often gives it back quite soon.
I hope there exist a lot of examples, and maybe this question will see a lot of great answers then. To specify the question, I am searching for opening ideas where:

In a position which is roughly equal, one side (player A) sacrifices a lot of material – more than a pawn, the more the better.
The other side (player B) has to take that material in order not to get a worse position.
After B grabs that material, A gets a playable position. (That does not mean sacrificing material had to be the best move available.)
Ideally these lines occur rather often in actual games. Such a trick on move 24 in an opening no one plays is of course less interesting.


user4362: When I answered your other question and mentioned that a semi-bluff sacrifice works better if the best counter is to take the material, I actually had a specific opening line in mind. 
I have never played the line with black myself, but I recommended it to a friend, who won some very nice games against stronger opposition.
The line I'm talking about is a sacrificial variation of the Löwenthal-Sicilian. You sac a pawn on your ninth move and continue with a rook sacrifice. The line I give below is just a sample line. There's quite a little tactical labyrinth for white to navigate. There is no direct refutation, only a better endgame for white in some line that I cannot remember. There are a lot of ways for white to go wrong, even if he doesn't take the rook for example, it can be quite tricky to get the knight out again. 
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 e5 5. Nb5 a6 6. Nd6+ Bxd6 
7. Qxd6 Qf6 8. Qd1 Qg6 9. Nc3 d5 10. Nxd5 Qxe4+ 11.Be3 Nd4 12.Nc7 Ke7
13. Nxa8 Nxc2 14. Kd2 Nxe3 15. fxe3 Nf6 16. Qb3 Rd8 17. Ke1 Ng4


4050: <p>There are some opening lines where grabbing material is very dangerous – <a href="https://chess.stackexchange.com/questions/8187/11-qg5-in-svesnikov-possible">another question of mine serves as a good example</a>.</p>

<p>However, are there some trick lines where the only reasonable choice is to grab extra material leading to a game playable for the player offering material? At first some gambits come to mind where one has to take a pawn first, but rather often gives it back quite soon.</p>

<p>I hope there exist a lot of examples, and maybe this question will see a lot of great answers then. To specify the question, I am searching for opening ideas where:</p>

<ul>
<li>In a position which is roughly equal, one side (player A) sacrifices a lot of material – more than a pawn, the more the better.</li>
<li>The other side (player B) has to take that material in order not to get a worse position.</li>
<li>After B grabs that material, A gets a playable position. (That does not mean sacrificing material had to be the best move available.)</li>
<li>Ideally these lines occur rather often in actual games. Such a trick on move 24 in an opening no one plays is of course less interesting.</li>
</ul>
 4362: <p>When I answered your other question and mentioned that a semi-bluff sacrifice works better if the best counter is to take the material, I actually had a specific opening line in mind. </p>

<p>I have never played the line with black myself, but I recommended it to a friend, who won some very nice games against stronger opposition.</p>

<p>The line I'm talking about is a sacrificial variation of the Löwenthal-Sicilian. You sac a pawn on your ninth move and continue with a rook sacrifice. The line I give below is just a sample line. There's quite a little tactical labyrinth for white to navigate. There is no direct refutation, only a better endgame for white in some line that I cannot remember. There are a lot of ways for white to go wrong, even if he doesn't take the rook for example, it can be quite tricky to get the knight out again. </p>

<pre><code>rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 e5 5. Nb5 a6 6. Nd6+ Bxd6 
7. Qxd6 Qf6 8. Qd1 Qg6 9. Nc3 d5 10. Nxd5 Qxe4+ 11.Be3 Nd4 12.Nc7 Ke7
13. Nxa8 Nxc2 14. Kd2 Nxe3 15. fxe3 Nf6 16. Qb3 Rd8 17. Ke1 Ng4
</code></pre>
