Back rank mates are the most common mates in chess. The books tell us to keep the 3 pawns in front of the King--The Praetorian Guard--intact but every rule must sometimes be broken. Moving one of the Pawns provides the King with needed ventilation and prevents Back Rank Mate. Here's an example of a simple Back Rank Mate in which the attacking party has a Queen and two Rooks.
FEN
r3r1k1/3R1ppp/p3p1q1/2p1B3/2p5/5Q2/PPP3PP/1K1R4 w - - 1 0
White plays and wins. To see the solution please select the area between the brackets.
[1.Qxa8 Rxa8 2. Rd8 Rxd8 3. Rxd8 MATE]
For more information click here.
Game example--Back Rank Corner Mate
Game Example--Bishop & Rook--Back Rank Center Mate
Game Example--Back Rank Center Mate--Knight & Bishop