'Tricollage'
3 authors, one map.
Each author takes one section. In the template (see below), the sections have walls between them; these walls belong to the section on the outside of them, not the middle section (ie. the left wall belongs to the left section, the right wall belongs to the right section). The outside authors can cut some parts out of the wall for the player to get in and out; it's probably best to leave most of the wall intact.
The player starts in the middle one (positioning is up to the middle author) and can then enter either the left or the right side. Each side has a fake 'exit switch'* that the player then gets to (after traversing all your standard level-y obstacles); the player then leaves, goes through to do the other side, and hits that switch, and comes back into the main section.
* which, for ease of identification, can be created as a real exit switch when the outside authors are making the level
Back to the authors: once the two outer sections are done, the last author creates the middle section. This middle section must include a real exit, and this exit needs to be made in such a way that the two fake exit switches need to be activated before the player can go through the exit*.
* so now the author can replace the fake exit switches, that were real exit switches, with door switches that activate doors surrounding (or whatever) the final, real exit
Blank template:
00000000000000000000000000000000001000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000010000000000000000000000000000000000000000000001000000000000000000000000000000000011111111111111111111111000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000010000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000011111111111111111111111000000000000000000000000000000000010000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000010000000000000000000000000000000000|
Example:
000000000000100000000000000000000001000000000001110000000011100000000001000000000001000111000010000000000010000010000100000000000000000111011100000000000000000000000000000000000000000000000000000000000000000111111001111111001111110000000000000000000000000000000000000000000000000000000003400000034000000000000311400003114000034000002111400311150000000000000011@?100000000000000000011A>10000000025000003111500211140000000000021150000211500000000000025000000250000000000000000000000000111111111<00;111111111100000000:=00:=0000000000000000000000000000000000;<000000000000000000000:=0000000000000000000000000000000000000000000000000000000000000;<000000000000000000000:=000000000000000000000000000000000000000000000000|5^408,276!1^660,228!1^660,300!1^660,372!1^660,444!1^660,156!9^636,540,1,0,17,22,1,0,-1!9^636,540,1,0,16,22,1,0,-1!9^60,540,1,0,16,21,1,0,-1!9^60,540,1,0,17,21,1,0,-1!7^396,300,3!7^420,300,3!3^492,60!3^300,60!9^132,132,0,0,4,16,1,0,0!9^132,132,0,0,4,17,1,0,0!9^132,132,0,0,4,18,1,0,0!9^132,36,0,0,4,17,1,-1,0!9^132,36,0,0,4,16,1,-1,0!9^132,36,0,0,4,18,1,-1,0!8^228,36,2!8^36,132,0!0^132,108!0^132,60!0^60,420!0^60,444!0^60,468!0^60,492!3^228,300!4^132,570,1!4^756,570,1!6^636,60,0,0,1,0!6^684,468,1,0,1,2!7^444,204,3!7^372,204,3!7^444,204,2!7^444,204,1!7^444,204,0!7^372,204,1!7^372,204,0!7^372,204,2!10^408,324!0^444,168!0^372,168!0^480,204!0^336,204!0^444,240!0^372,240!0^408,204!0^696,96!0^720,120!0^744,96!0^720,72!0^720,96!0^738,78!0^702,78!0^702,114!0^738,114!0^732,96!0^708,96!0^720,84!0^720,108!12^432,408!12^384,408!12^456,408!12^360,408!12^468,444!12^468,372!12^348,372!12^348,444!0^480,396!0^480,420!0^336,396!0^336,420!0^492,408!0^324,408!10^408,408!11^408,480,408,120