For invulnerability in this game, use the DOS utility DEBUG.
 First backup your game to be edited, then type the following
 from the dos prompt:

 For the [CGA] version of this game, type:

 ren e:\roller.exe cheater.cht
 debug e:\cheater.cht
 e 1e8d 90 90 90 90
 e 31c7 75
 w
 q

 For the [EGA] version of this game, type:
 ren e:\roller.exe cheater.cht
 debug e:\cheater.cht
 e 1e62 90 90 90 90
 w
 q

 Then rename CHEATER.CHT back to its previous name.