Enter "RONALDSIU" as a password to unlock the Banana Peel card.
Card upgrades
Upgrade the following cards to receive different ones. Note: All upgraded cards will count as a different card than the original.
Strand will upgrade to Critical Shot.
Equipment Lv.2 will upgrade to Equipment Lv.3.
Bandage will upgrade to Syptic +.
McDonnell Miller will upgrade to Liquid Snake.
Gray Fox will upgrade to Cyborg Ninja.
Ocelot will upgrade to Revolver Ocelot.
Metal Gear D Revised will upgrade to Metal Gear Mk-II.
Django will upgrade to Sabata.
Otenko Sama will upgrade to Otenko Sama +.
Naked Snake will upgrade to Big Boss.
Completion bonuses
Successfully complete the game to unlock the "Card Movies" option in the Deck Editor and Metal Gear REX and MGS 4 cards in your deck. Play a bit further (past the first part of stage 3) after completing the game once to unlock the MGS3: Subsistence pack. Successfully complete the game two times to unlock the Metal Gear RAY card, MGS Integral pack, MGS2 Substance pack, and Chronicle Unlimited.
Control title screen
Use the Analog-stick to scroll up and down. Press L to change the color of the "Metal Gear Ac!d 2" text to black and remove the black pixel effect. Press R to zoom in on the title screen. Upon zooming in you will have the freedom to "scroll" the Analog-stick.
Decoy Octopus card (No. 203)
Enter "DCY" as a password to unlock the Decoy Octopus card (No. 203). Enter "DCYCTPS" as a password in the Japanese version of the game.
Emma's Parrot card
Enter "GINORMOUSJ" as a password to unlock the Emma's Parrot card.
EZ Gun
Successfully complete Arena mode half way on the Easy difficulty setting to unlock the EZ Gun.
G36C
Successfully complete Arena mode half way on the Extreme difficulty setting to unlock the G36C.
Gekko
Enter "GEKKO" as a password to unlock the Gekko.
Gijin-san card (No. 099)
Enter "SHINTA" as a password to unlock the Gijin-san card (No. 099). Enter "CCT" as a password in the Japanese version of the game.
Ishii Meguru card (No. 286)
Enter "MGR" as a password to unlock the Ishii Meguru card (No. 286). Enter "SHIIMEG" as a password in the Japanese version of the game.
Jack card (No. 291)
Enter "SONOFSULLY" as a password to unlock the Jack card (No. 291). The Jack card allows you to move one extra space when you move, but your attack is reduced by 20 points. This effect lasts three turns.
Jehuty card (No. 172)
Enter "JEHUTY" as a password to unlock the Jehuty card (No. 172).
Karen Houjou card (No. 170)
Enter "KAREN" as a password to unlock the Karen Houjou card (No. 170).
Kinoshita Ayumi card (No. 285)
Enter "AYM" as a password to unlock the Kinoshita Ayumi card (No. 285). Enter "KINOSHITAA" as a password in the Japanese version of the game.
Metal Gear MK. II MGS4 card
Enter "MK2" as a password to unlock the Metal Gear MK. II MGS4 card.
MGS4 card (No. 288)
Enter "NEXTGEN" as a password to unlock the MGS4 card (No. 288). Enter "NO PLACE" as a password in the Japanese version of the game.
Mika Slayton card (No. 166)
Enter "MIKA" as a password to unlock the Mika Slayton card (No. 166).
Mr. Sigint card (No. 188)
Enter "SIGNT" as a password to unlock the Mr. Sigint card (No. 188). Enter "SGNT" as a password in the Japanese version of the game.
Natsume Sano card (No. 287)
Enter "NTM" as a password to unlock the Natsume Sano card (No. 287). Enter "NONAT" as a password in the Japanese version of the game. Note: This also unlocks the "Solid Eye" video.
No Smoking card
Enter "SMOKING" as a password to unlock the No Smoking card.
Otacon MGS4 card (No. 295)
Enter "OTACON" as a password to unlock the Otacon MGS4 card (No. 295).
Possessed Arm card
Enter "THESPANIARD" as a password to unlock the Possessed Arm card.
Reaction Block card (No. 119)
Enter "KONAMI" as a password to unlock the Reaction Block card (No. 119).
Reiko Hinomoto card (No. 281)
Enter "HNMT" as a password to unlock the Reiko Hinomoto card (No. 281). Enter "XX" as a password in the Japanese version of the game.
Roger McCoy card (No. 212)
Enter "MCCY" as a password to unlock the Roger McCoy card (No. 212). Enter "RGR" as a password in the Japanese version of the game.
Running Man
Successfully complete Arena mode half way on the Hard difficulty setting to unlock the Running Man.
Sea Harrier card (No. 197)
Enter "SHRRR" as a password to unlock the Sea Harrier card (No. 197). Enter "HRRR" as a password in the Japanese version of the game.
Solid Eye card
Enter "TOBIDACID" as a password to unlock the Solid Eye card.
Solid Snake MGS4 card (No. 294)
Enter "SNAKE" as a password to unlock the Solid Snake MGS4 card (No. 294). This card sets your equipment level to 3. It has a picture of Solid Snake with gray hair and an eye patch.
Stealth
Successfully complete Arena mode half way on the Normal difficulty setting to unlock the Stealth.
Strain card (No. 046)
Enter "NOJIRI" as a password to unlock the Strain card (No. 046). Enter "VRS" as a password in the Japanese version of the game.
Viper card (No. 161)
Enter "VIPER" as a password to unlock the Viper card (No. 161).
XM Eight card (No. 187)
Enter "XM8" as a password to unlock the XM Eight card (No. 187).