Enter on the VS screen. Each code is 6 digits — Player 1 controls left 3, Player 2 controls right 3.
Change digits with LP / BL / LK buttons.
| CODE | EFFECT | NOTES |
|---|---|---|
| 0-0-0 0-0-0 | No Cheats | Default |
| 9-8-9 9-8-9 | Unlimited Run | Run meter never depletes |
| 0-0-0 2-0-2 | Explosive Kombat | Moves cause explosions |
| 4-6-6 4-6-6 | Randper Kombat | Characters change randomly |
| 0-8-0 0-8-0 | Galaga | Mini-game instead of match |
| 1-0-0 1-0-0 | Arm Ripped Off Mode | Uppercuts rip arms |
| 0-3-3 0-0-0 | Invisible Player 1 | |
| 0-0-0 0-3-3 | Invisible Player 2 | |
| 0-3-3 0-3-3 | Both Invisible | |
| 7-7-7 7-7-7 | No Power Bars | Health hidden for both |
| 0-4-4 4-4-0 | Psycho Kombat | Invisible + No power bars |
| 5-5-5 5-5-5 | Combo Breaker | Shake out of combos |
| 0-2-0 0-2-0 | Winner Fights Shao Kahn | Winner fights Kahn next |
| 9-6-9 1-4-1 | Random Kombat | Both chars random |
| 9-0-4 4-0-9 | Red Rain | Kitana's fan stage effect |
| 2-0-5 2-0-5 | Ermac Hint | Ermac message on screen |
| 1-9-9 1-9-9 | No Fear | Promo code |
Same VS-screen system as UMK3. Key codes for MK3:
| CODE | EFFECT | NOTES |
|---|---|---|
| 9-8-9 9-8-9 | Unlimited Run | Same as UMK3 |
| 4-6-6 4-6-6 | Randper Kombat | |
| 0-8-0 0-8-0 | Galaga | |
| 1-0-0 1-0-0 | Arm Ripped Off Mode | |
| 0-3-3 0-3-3 | Both Invisible | |
| 7-7-7 7-7-7 | No Power Bars | |
| 0-4-4 4-4-0 | Psycho Kombat | Invisible + No bars |
| 1-9-9 1-9-9 | No Fear |
D=Down · U=Up · B=Back · F=Forward · LP=Lo Punch · HP=Hi Punch · LK=Lo Kick · HK=Hi Kick · BL=Block · RN=Run
Direction is relative to your fighter's side. ✦ CLOSE / SWEEP / ANYWHERE noted per move.