How to Get and Install Source SDK and L4D1/2 Tools

How to get and install Source™ SDK and L4D1/2 Authoring Tools?

How to begin creating maps for any of Valve games?

I get this question asked a lot. In this tutorial you will learn everything you need to know how to get the Source SDK and L4D1/2 Authoring Tools.

BASICS:

SOURCE™ = game engine from Valve

SOURCE SDK = Source Software Development Kit. For Games such as HL2, HL2: EP1/2, Portal, CS:S, DoD:S, TF2.

L4D1/2 Authoring Tools = Source Software Development Kit for L4D1/2.

Hammer: Source = Level Editor for Source based games.

If you want to create maps and custom content for HL2, HL2: EP1/2, Portal, CS:S, DoD:S, TF2 you need Source SKD.
If you want to create maps and custom content for L4D1/2 you need L4D1/2 Authoring Tools.

WHAT YOU NEED:

1. Purchase the Game

Any of the following games purchased and installed: PC version only.

Half-Life 2
Half-Life 2: Episode Pack
Portal
Portal 2
Counter-Strike: Source
>Day of Defeat: Source
Team Fortress 2 (free to play and free to download)
Left 4 Dead
Left 4 Dead 2
The Orange Box (contains TF2, Portal, HL2: EP2)
>Half-Life 2: Game of the Year Edition (contains HL2, HL:Source, CS:S, HL2: Deathmatch)

You can purchase the above games from the walk-in stores, online stores, Amazon, Gamestops etc. You can also purchase any of these games from Steam.

2. Install Steam

You can download Steam from here. Steam is required for you to authenticate Valve games. You can purchase any games from the above list as well.

Steam will also be installed if you bought the games from anywhere other then Steam's website.

3. Launch Steam

Launch Steam and head over to Library --> Games. Here you will find a list of games that you own.

4. Download Source SDK or L4D1/2 Authoring Tools

Download Source SDK or/and L4D1/2 Authoring Tools by going to Library --> Tools in Steams interface.

If you want to create maps and custom content for HL2, HL2: EP1/2, Portal, CS:S, DoD:S, TF2 you need Source SKD.
If you want to create maps and custom content for L4D1/2 you need L4D1/2 Authoring Tools.