what game do you want to know the cheat for...
i can tell you for this game anyways...
have the pokemon you want to duplicate in your party (you can give it an item if you want that duplicated too...)
now once you have that, go to any pokemon centre p.c, and save it before you click on the p.c
now go to deposit and deposit the pokemon you want duplicated...
now change to any empty box, and while it says "savong to not turn off the power" turn off the power
turn the game back on, one of your duplicated pokemon will be in your party, and the other in your p.c
Join this site...http://s14.invisionfree.com/ChaoticRoleplayRealm/index.php?
and this one...http://gameknot.com/?rfr=diezombie...when you sign up the second one, where it says referals by, type in diezombie