Airship Passwords
The airship in Final Fantasy X International has several locations that are only accessible by entering the correct password. These passwords involve clues scattered around the world that are written in the Al Bhed language. It can be time consuming to find these clues and learn enough Al Bhed to understand them.
Entering ̶0;GODHAND̶1; will take you to the chest containing Rikku̵7;s ultimate weapon. Entering ̶0;VICTORIOUS̶1; will take you to a chest containing a very good piece of armor for Rikku. Entering ̶0;MURASAME̶1; will take you to a chest containing a weapon for Auron that will reduce the cost of all his spells to 1 MP. This can be a very good (or useless) weapon depending on how many spells Auron knows.
Easy Blitzball Wins
The AI in the blitzball mini-game contains a small glitch that can be exploited to allow the player to easily win. You need to have a higher score than your opponent and have possession of the ball to use this cheat. Simply take the ball behind your own goal and swim around in a circle. The enemy AI will almost never swim this far into your side of the field. This should allow you to run down the clock and win the match.
Easily Defeat Evrae Altana
Evrae Altana is a boss in Final Fantasy X International. It is actually the zombie form of Evrae, a boss you will defeat right before fighting Evrae Altana. This boss can easily be defeated by exploiting the fact that the boss is undead. Use ̶0;Phoenix Downs̶1; on it with the ̶0;Item̶1; command. It will die after about three uses of the item.