ruby - Refactoring conditional variable assignment -

I am working on a project. Currently I have a large conditional statement, which provides a value for variables based on some input parameters. So, I have something like that.

  If some condition x = some value alsf another condition x = a different value ...   
 What's the best way to refact this ? I hope I can end up with something like this  
  x = some value if some condition ||   
 Is there a pattern for this type of thing?   
 
Michael Elkan