Valve is kicking off the recent release of SDK libraries for Portal 2 in a big way, announcing a contest called the 2011 Summer Mapping Initiative. It invites designers to craft original maps for Portal 2, of either the single-player or co-op variant.

Up for grabs is an Ultimate Portal 2 Gift Pack signed by the Portal 2 developers. Additionally, for extra bragging rights, your creation will be featured on Valve’s own Portal 2 site and community hub ThinkingWithPortals.com. We’ve included the official rules below.  Entries must be submitted by June 6 at 11:59pm EDT.

• Maps must be submitted no later than June 6th at 11:59pm EDT.
• Both Singleplayer and Co-op maps are allowed. You may submit one map of each game mode.
• Maps cannot contain custom assets of any kind. No exceptions. Spend your time working on your puzzle, not making models, textures, sounds/voices, or other extra content.
• Maps must contain both an Entry and an Exit elevator, the style of which as appropriate for your map theme. 1940’s Aperture maps can use the old style elevators, destroyed Aperture can use the destroyed looking elevators, and so on.
• Maps must be able to be completed without using engine or portaling glitches of any kind.
• Entries must be uploaded to the ThinkingWithPortals.com Download Database and uploaded in a compressed file format (such as ZIP, RAR or 7z).
• Entries must include the source VMF.

Hit up the official contest page for more details.

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