The following are known Game Genie Codes for Seiken Densetsu 3 on Super Nintendo (SNES).

Note: Pretty much the bulk of these codes need to be entered at the start of a new game.
• 9,999,999 Luc (Money) After Battle
  DBA7-556F
• No Stat-Raising Limit
  DDA2-710D
• Class Change At Any Level
  DD7E-EFBF
• Gain Access To Duran’s And Hawk’s First Level Special Attack (Infinite Use)
  D03E-9E7E
  EE3E-BE7E
• Gain Access To Duran’s And Hawk’s Second Level Special Attack (Infinite Use)
  DB3E-9E7E
  EE3E-BE7E
• Gain Access To Angela’s First Level Special Attack (Infinite Use)
  D0EE-FE7A
  EEE3-9EFA
• Gain Access To Angela’s Second Level Special Attack (Infinite Use)
  DBEE-FE7A
  EEE3-9EFA
• Gain Access To Kevin’s First Level Special Attack (Infinite Use)
  D03E-9E7E
  EE33-BE5E
• Gain Access To Kevin’s Second Level Special Attack (Infinite Use)
  DB3E-9E7E
  EE33-BE5E
• Enemies Die With 1 Hit
  1032-806D
• Walk Through Walls
  1DF8-8FA1
• Can Get Any Item From Storage
  CBE6-EF9F
  DD32-7561
  Note: Press SELECT to access the Item Storage.

Duran Codes

• Duran’s HP Is Increased From 88 To 118, His Vitality Is Increased From 5 To 25, And His Defense Is Increased From 9 To 29 1
  FB78-8065
• Duran’s MP Is Increased From 6 To 29, His Intellect Is Increased From 2 To 25, And His Magic Defense Is Increased From 18 To 110
  FB78-80A5
• Duran’s Strength Is Increased From 6 To 25, And His Attack Is Increased From 18 To 56
  FB78-80D5
• Duran’s Agility Is Increased From 4 To 25, And His Evade Rate Is Increased From 11 To 41
  FB78-8005
• Duran’s MP Is Increased From 6 To 29, And His Spirit Is Increased From 2 To 25
  FB78-89D5
• Duran’s Luck Is Increased From 2 To 25, And His Evade Rate Is Increased From 11 To 22
  FB78-8905

Kevin Codes

• Kevin’s HP Is Increased From 90 To 118, His Vitality Is Increased From 6 To 25, And His Defense Is Increased From 9 To 28
  FB74-E165
• Kevin’s MP Is Increased From 6 To 29, His Intellect Is Increased From 2 To 25, And His Magic Defense Is Increased From 17 To 109
  FB74-E1A5
• Kevin’s Strength Is Increased From 4 To 25, And His Attack Is Increased From 16 To 58
  FB74-E1D5
• Kevin’s Agility Is Increased From 3 To 25, And His Evade Rate Is Increased From 10 To 41
  FB74-E105
• Kevin’s MP Is Increased From 6 To 29, And His Spirit Is Increased From 2 To 25
  FB74-E5D5
• Kevin’s Luck Is Increased From 2 To 25, And His Evade Rate Is Increased From 10 To 21
  FB74-E505

Hawk Codes

• Hawk’s HP Is Increased From 86 To 119, His Vitality Is Increased From 3 To 25, And His Defense Is Increased From 8 To 30
  FB7C-E065
• Hawk’s MP Is Increased From 8 To 30, His Intellect Is Increased From 3 To 25, And His Magic Defense Is Increased From 19 To 107
  FB7C-E0A5
• Hawk’s Strength Is Increased From 3 To 25, And His Attack Is Increased From 15 To 59
  FB7C-E0D5
• Hawk’s Agility Is Increased From 6 To 25, And His Evade Rate Is Increased From 16 To 43
  FB7C-E005
• Hawk’s MP Is Increased From 8 To 30, And His Spirit Is Increased From 3 To 25
  FB7C-E9D5
• Hawk’s Luck Is Increased From 6 To 25, And His Evade Rate Is Increased From 16 To 25
  FB7C-E905

Angela Codes

• Angela’s HP Is Increased From 84 To 118, Her Vitality Is Increased From 2 To 25, And Her Defense Is Increased From 7 To 30
  FB0F-7160
• Angela’s MP Is Increased From 13 To 32, Her Intellect Is Increased From 6 To 25, And Her Magic Defense Is Increased From 24 To 100
  FB0F-71A0
• Angela’s Strength Is Increased From 2 To 25, And Her Attack Is Increased From 14 To 60
  FB0F-71D0
• Angela’s Agility Is Increased From 2 To 25, And Her Evade Rate Is Increased From 9 To 42
  FB0F-7100
• Angela’s MP Is Increased From 13 To 32, And Her Spirit Is Increased From 5 To 25
  FB0F-75D0
• Angela’s Luck Is Increased From 4 To 25, And Her Evade Rate Is Increased From 9 To 19
  FB0F-7500

Carlie Codes

• Carlie’s HP Is Increased From 84 To 118, Her Vitality Is Increased From 2 To 25, And Her Defense Is Increased From 7 To 30
  FB0B-7060
• Carlie’s MP Is Increased From 13 To 32, Her Intellect Is Increased From 5 To 25, And Her Magic Defense Is Increased From 21 To 101
  FB0B-70A0
• Carlie’s Strength Is Increased From 2 To 25, And Her Attack Is Increased From 14 To 60
  FB0B-70D0
• Carlie’s Agility Is Increased From 2 To 25, And Her Evade Rate Is Increased From 9 To 42
  FB0B-7000
• Carlie’s MP Is Increased From 13 To 32, And Her Spirit Is Increased From 6 To 25
  FB0B-79D0
• Carlie’s Luck Is Increased From 5 To 25, And Her Evade Rate Is Increased From 9 To 19
  FB0B-7900

Lise Codes

• Lise’s HP Is Increased From 87 To 118, Her Vitality Is Increased From 4 To 25, And Her Defense Is Increased From 8 To 29
  FB0D-5160
• Lise’s MP Is Increased From 9 To 30, Her Intellect Is Increased From 4 To 25, And Her Magic Defense Is Increased From 20 To 104
  FB0D-51A0
• Lise’s Strength Is Increased From 5 To 25, And Her Attack Is Increased From 17 To 57
  FB0D-51D0
• Lise’s Agility Is Increased From 5 To 25, And Her Evade Rate Is Increased From 13 To 41
  FB0D-5100
• Lise’s MP Is Increased From 9 To 30, And Her Spirit Is Increased From 4 To 25
  FB0D-55D0
• Lise’s Luck Is Increased From 3 To 25, And Her Evade Rate Is Increased From 13 To 24
  FB0D-5500