As stated when you click the "View Rules" button on the Arcade Category (assuming you're inquiring for Arcade):
Difficulty: Very Hard
We require that all top place times (1st - 3rd) be performed live. Permitted Arcade Emulators: -WolfMame In order to qualify for a top time, you MUST be running on Wolfmame & an inp recording must be submitted with each attempt to the appropriate moderator in the discord link here [ https://discord.gg/5CcDck7 ] A guide to inp creation can be found at [ https://www.speedrun.com/mk1/guide/euoqg ]
Permitted Arcade-Perfect Ports: -Official Arcade/MAME Revisions -MK Arcade Kollection (PSN, XBLA, and PC) -UMK3 for XBLA -Nintendo DS
Acceptable Arcade revisions: -Revision 1.0, 1.1, and 1.2
Special Rules: -You must select the Master II tower. -The timer starts when the tower is selected and stops when the final blow is delivered to Shao Khan.
*Please note: The use of TAS is strictly prohibited.
While I am specifically only a Moderator for Mortal Kombat 1, these rules are universal across MK1,2,3 and UMK3 for Arcade (although of course, allowed revisions and ports may vary). Please let us know if you need any clarification on anything.
