When the game is initialised i want the 8051 to be able to genarate a word at random
Dead easy, require the user to press a key to indicate "start of game". While waiting for that key to be pressed run a loop such as

WaitForStart:
inc dptr
jb KeyPressed,EndOfWait
sjmp WaitForStart
EndOfWait:
mov dph,HighRandomNumber
mov dpl,LowRandomNumber

This will even give you a truly random number since the loop will rin in abt 200ms and the keypress wait will be more than that.

Erik