You make a new lump called MAPxxD (xx being the map number you are using) or MAINCFG.
Level x
LevelName = x
Act = x
MusicSlot = x
NextLevel = x
TypeOfLevel = x
SkyNum = x
That is it, but there are other fields.
Level [map number]
LevelName = [map name]
Act = [act number]
MusicSlot = [music number]
- 1. Greenflower Zone Act 1
2. Greenflower Zone Act 2
3. Boss
4. Techno Hill Zone Act 1
5. Techno Hill Zone Act 2
7. Castle Eggman Zone Act 1
8. Castle Eggman Zone Act 2
9. Castle Eggman Zone Act 3
11. Mine Maze Zone Act 1
13. Rocky Mountain Zone Act 1
14. Arid Canyon Zone Act 1
16. Red Volcano Zone Act 1
19. Dark City Zone Act 1
22. Doomship Zone Act 1
29. Spring Hill Zone (Nights)
30. Mario Koopa Blast Act 1
31. Mario Koopa Blast Act 2
32. Mario Koopa Blast Act 3
42. Metal Harbor
45. Green Hill Zone
50. Special Stage
90. Deep Sea Zone Act 2
91. Meadow Match Zone
92. Airborne Temple Zone
93. Sapphire Falls Zone
94. Hydro Plant Zone
95. Deep Sea Zone Act 1
96. Zero Ring Zone
97. Zim's Base Zone
98. Desolate Twilight Zone
100. Xmas Greenflower Zone Act 1
101. Xmas Greenflower Zone Act 2
102. Xmas Boss
103. Xmas Techno Hill Zone Act 1
104. Xmas Techno Hill Zone Act 2
105. Xmas Castle Eggman Zone Act 1
106. Xmas Castle Eggman Zone Act 2
107. Xmas Castle Eggman Zone Act 3
108. Xmas Spring Hill Zone (Nights)
135. Mystic Realm Boss
136. Jade Coast Zone
137. Tempest Valley Zone
138. Verdant Forest Zone
139. Flame Rift Zone
140. Midnight Freeze Zone
141. Sunken Plant Zone
142. Aerial Garden Zone Act 1-2
143. Aerial Garden Zone Act 3-4
144. Prismatic Angel Zone
145. Mystic Realm Zone
1036. Title
1037. Intro
1038. Level Clear
1039. Invincibility
1040. Super Sneakers
1041. Mario Invincibility
1042. Drowning
1043. Game Over
1044. Extra Life
1045. Continue
1046. Super Sonic
1047. Character Select
1048. Credits
1049. Multiplayer Intermission
NextLevel = [level number]
TypeOfLevel = [value]
- 1. Cooperative
2. Race
4. Match
8. Tag
16. Capture the Flag
64. Nights
128. Sonic Adventure
256. Mario
512. 2D
1024. Xmas
4096. Single Player
SkyNum = [slot number]
- 1. Greenflower Zone
4. Techno Hill Zone
7. Castle Eggman Zone
8. Castle Eggman Zone Beta
29. Spring Hill Zone (Nights)
30. Mario Koopa Blast Act 1
31. Christmas Hunt
54. Wood Zone
56. Black
60. Special Stage 1
61. Special Stage 2
62. Special Stage 3
63. Special Stage 4
64. Special Stage 5
65. Special Stage 6
66. Special Stage 7
94. Starry Sky
96. Starry Sky with Planet
97. Zim's Base Zone
ForceCharacter = [character number]
- 0. Sonic
1. Tails
2. Knuckles
Weather = [slot number]
- 0. Nothing
1. Thunderstorm
2. Snow
3. Rain
NoZone = [0 or 1]
Hidden = [0 or 1] (hidden from level select)
Countdown = [time in seconds]
NoSSMusic = [0 or 1]
NoReload = [0 or 1] (reload the entire level from beginning or not)
ScriptName = [name] (name of a script you want to run on load)
ScriptIsLump = [0 or 1] (if the script you want to run on load is a separate file or a lump)
PreCutsceneNum = [slot number] *
CutsceneNum = [slot number] *
*Cutscenes are created with SOCs.
I simplified it for messageboard use.
Edit: Someone answered before me! Oops! ^^'