I have very fast Internet (80 Mbps), but not unlimited bandwidth. I can download at most 240 GB per month. Unfortunately, I have about two terabytes of Steam games. If I ever lose them, it will take months to download them all again, so I do keep a backup. This paid off just a couple of weeks ago when my disk started dying. Without that backup, I would probably have ended up in a mental institute. ;-)

You do know that you don't need to have all the games you own installed at the same time, you can... well... only install the ones you are actually playing.

Yes, but I choose to have all my games available to me all the time. I download my games when I buy them and if I run out of space, I buy a bigger disk. I figure that my new 3 TB disk will last me a while. They aren't writing games as fast as I buy them ;)

I can't understand the reasoning behind this, but well... It has to be amusing to watch a situation when your 3TB hard drive breaks down :P

If you back up the steamapps folder directly as others have recommended note that when you restore it Steam will say the games aren't installed. This is normal. Simply tell each of the backed up games to install and Steam will start checking the file integrity. The game will be listed as "downloading" while this happens but no actual transfer occurs unless the game has been updated since you made your backup. Steam will then start the first-time install process and everything works as expected.

You can use this same trick with other services such as Origin and the Games for Windows Marketplace, but for them you'll need to back up the installer files, not the completed install.

This method also works with MMORPGs and the like that have a small initial install and then download the rest of the files through the launcher; any files that already exist will be skipped unless they have been updated on the server end.

When it does, I swap it out with the replacement on which I made the backup. I wouldn't call it amusing, but it's hardly dramatic. Like I said, this happened to me a few weeks ago and my backup saved the day. No fuss, no muss.

As to the reasoning, it's simple. When I get an urge to play a game, it's there. I boot up, launch the game, and I'm playing. Would you buy a car and leave it at the dealership until you decide to use it? Of course not. You'd keep it in YOUR driveway so when you need it, you just hop in and drive. If I didn't plan on playing it, I wouldn't have bought it. :)
By the way, this also works when you have a corrupted registry (Norton Utilities, for example, kills the steam registry entries) and your games won't start. Just move your steamapps directory off to somewhere else, uninstall steam, reinstall steam, and move the original steamapps directory back where it belongs. Your registry entries will be all fixed and your games will run like new.

I don't backup games; if I wanted to have to hassle with finding disks, or wasting space on hard-drives for something I'll rarely play again I'd just stick to buying discs instead of using services like Steam or GOG.

I have a severe lack of morals so that if GOG goes under I'll just pirate the games I bought and might want to play, same goes for Steam.

+1

Lazy, indeed! I've pretty much stopped using discs since I've joined the digital bandwagon.

The only stuff worth backing up is my GOG and Indie collection. Got a portable HDD for that. I've thought about eventually burning my GOG games onto DVDs, but I'm not sure yet whether it's actually worth it.

I using dual-boot with 2 harddisks. I just copy my Steamapps folder over from the older harddisk to the newer one. Havent actually backup the folder into my external harddisk, figured it was not worth the effort because of Steam's DRM. My GoG games are kept preciously on my harddisks, my external harddisk and my DVDs though.

No, I do not back them up.

I follow the old saying that 'if you lend something, you consider it gone until you get it back'. With steam, I have lent them my trust that they will continue to provide the games, but I would never trust them with a game I couldn't stand to lose.

Also, the odds that I lose my games because steam goes under, are greatly eclipsed by the 1984 style future that games companies are going for, where I'll lose all my games for speaking ill of them on forums. So at that point it would be no different for me to continue to use my downloaded copy, compared to just getting a pirate copy (not sure I'd bother, as per the first paragraph). So why would I waste space backing up?

i have tested out a few times , like others have said you have to put the client into offline mode when you are online for it to work properly , which makes no sense , oh well ...if the client fails then im screwed or not thanks to drm free games :D best of both worlds

You know that there's backup option in steam app, don't you?
You don't backup your car :P Better analogy is like this: You would buy ALL cereal flavours, because you don't know which one you'd like to eat next week, so you buy them all, just in case :P

Yes, but it requires connecting to steam to validate anyway, so all it does is save some time compared to just redownloading the whole thing. Backing up the whole folder is faster still.

I was about to reply and say that simply copying the folder takes up more space because the backup option compresses them. But I checked before I opened my mouth - its not as clear cut as that. Some games save a little space others none at all - too much un-compressible (already compressed) binary data I suppose.

I might consider the "just copy the folder" option in future.