Armored Core 2 Codes -

Add defeated AC emblems:
Push Choose + when you see victory message appears in the arena to add the defeated AC's emblem to your list.

Steal Emblems:
If you see an emblem in the arena that you want to use, Choose the appropriate AC and press to display the spec screen. Then, press + Choose. A sound will confirm correct code entry. Choose Edit Emblem to view it.

Temporary invincibility:
Press + + . A Limiter Released system error message will appear, and you will have unlimited energy during this time. After approximately one minute, the OB Down system error will appear. It will last as long as the previous error, but you will not have any energy. After OB Down is completed, your AC will recharge and return to normal. Make sure you finish off your enemy before you become vulnerable.