This code only works for the end of the game! After you get the punching glove for Rudy go into any Elw Temple and walk up right next to the transporter. Quickly hit it with the glove and the run in. Continue doing this until you get stuck in the sattelite the you would normally bounce off of. When you go inside you will be in the Abyss. Consider it carefuly before you leave because it takes a long time to get back in!
Item Duplication Trick
1. Make sure that the item you want to duplicate is exactly one, like a medicine.
2. Enter a battle.
3. In the first round, have Rudy use an item, such as a power apple.
4. Have Jack switch the position of the power apple and medicine (or whatever item you want to duplicate).
5. Have Cecilla defend.
6. In the second round, have Rudy use the power apple again. You will see that the medicine is gone.
7. Have Jack switch back the position of the power apple with the medicine (now an empty space).
7. Have Cecilia defend.
8. In the empty space where the medicine used to be there should be 255 medicines.
Money and Exp. Heaven
Go to the island where the Ancient Arena is, there are islands directly east of it. The first island will do fine. Walk around there and there will be battles that should be easy depending on your level. Eventually you will encounter two very strange creatures called hayokanton (not the exact name, i think), defeat them and they will give a very high amount of money and exp. (very high) use a lucky card to get even more, if you run out of lucky cards, go back to the Ancient arena and fight the first round and then quit you will get a lucky card and a couple of other items. When you fight these monsters Arch Smash, Magnum Fang (for more fast draw attacks, duplicate a secret sign to make every attack 1 mp) work pretty good but then again you might find something that works better.
NOTE* these enemies can be hard on the islands depending on your level and they have strong attacks that have status changing effects (poison,curse,disease, etc. but be aware that it will not be only one status change) use a full Libra or even better duplicate the Sheriff Star from the abyss it will help greatly. One of the best tactics is to focus on one then the other.
Temple of Memory
The password for the Memory Temple is "Emiko".
During a battle insert a second controller into slot 2. And the person with the second controller can use the characters also.