How to map for portal? Free version?

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Download ‘Source SDK’ from Library>Tools and get cracking.

The free copy of portal does not include the SDK. You need to own another source game.

Buy the orange box and bathe in it’s glorious content.

The free portal doesn’t get SDK, so just buy the orange box if you want lots more content and much more games to map for.

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then it should be under tools tab

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