The Richter/Rauzer Attack is a continuation to the Sicilian Defense chess opening. I have seen different orders of play but all the pieces that are moved before, 6.Bg5, must be moved. I use this attack whenever my black opponent plays 2. ... Nc5. Here is the chess notation,
1. e4 c5 
2. Nf3 Nc5 
3. d4 cxd4 
4. Nxd4 Nf6 (I’m not sure why nobody plays 4. ... NxNd4)
5. Nc3  d6
6. Bg5 (this makes it The Richter/Rauzer)
There are different ways of proceeding at this point but the general idea is to put pressure on blacks queen to threaten to either exchange queens in a way that takes away blacks ability to castle or to take blacks queen. Here is a good demonstration of the Richter-Rauzer which is also where the opening gets its name,

Richter-Wagner, 1932

1. e4 c5 
2. Nf3 Nc6 
3. d4 cxd4 
4. Nxd4 Nf6 
5. Nc3 d6 
6. Bg5 e6 
7. Nxc6 bxc6 
8. e5 dxe5 
9. Qf3 Rb8 
10. Rd1 Qc7 
11. Ne4 Bb4+ 
12. c3 Nxe4 
13. Bd8!! Qb7 
14. Qxe4 Bf8 
15. Qxe5 Bd7 
16. Ba6!! f6 
17. Bxf6 gxf6 
18. Qh5+ black loses the Queen
For the full list of variations see ECO chess codes B6.

chess openings