The Collaborative International Dictionary
To play rex
Rex \Rex\, n.; pl. Reges. [L.] A king.
To play rex, to play the king; to domineer. [Obs.]
Usage examples of "to play rex".
And if you really want Harrison Ford to play Rex in the film version, you are cutting down the chances when he reads the script and says, 'So I get killed on page 82 do I?