This name of this popular American game is often shortened to ERS or alternatively ERF. It is also sometimes known as Egyptian War, Bloodystump or Slap. It is based on the English children's game known as "Beggar My Neighbour" or "Beat Your Neighbour Out Of Doors", with the additional rules that allow the pile to be won by slapping.
For the rules, please refer to Oxymoron's Egyptian Ratscrew Page.
A computer version of Egyptian Ratscrew is available for download from Chris Allen's web site.
Fedil Grogan has produced a Ratscrew app for iPhone or iPad.
At Eric Nie's playcards.club you can play Egyptian Ratscrew online.