I downloaded everything after GOG introduced regional pricing.
If they bow to the publishers, they will soon introduce a region block and also bow to censorship. After all this post basically says: "F**k germany!"

Luckily that doesn't seem to be a problem anymore but I wanted to back up my games anyway because I bought a NAS last year. Not just for GOG-games but as long as I have enough space left I'll use it for GOG.

In very few cases updated game files can be incompatible with some fan patches. I think there was also some game that had audio file format changed, if that makes a difference.

For most games, it doesn't matter, guess.

However, you should also download extras and Mac versions, just in case. At least one game had a soundtrack which was later removed, and a couple games had a Mac version first, but then it was pulled.

So download everything once, just to be on the safe side.

I download them all. I consider GOG's website to be my game folder security backup, not the other way round.

I download everything on or soon after purchase.

I remember the move out of beta...

I usually download them right after purchase. Been thinking about getting a portable hard drive (like 100GB or so) for storing all my games + bonus features. I do have a thumb drive that has an assortment of games backed up on it though. (Just the smaller ones, it can only fit so much lol)

At first I downloaded and backed up every one on my current hard drive, but I then clogged my hard drive and had little space for much else. I think it also began slowing down my system, but maybe that was my imagination...

I un-installed pretty much every game I didn't have a file going on or that I wasn't going to play any time soon. I'm taking a chance by keeping my collection solely on GOG right now, but until I can afford the 4 TB external mobile USB drive I've been eying, it's going to be too hard for me to download the hundreds of games I own. I could just go with a 2 TB one to start, since it's literally half the price. But we'll see.

I guess I am in the majority, I download all my games immediately after purchase. I also install and load every game too, to make sure they are working properly (at least as far as I can determine by playing them for a few minutes). Some games I then continue playing more fully, others go into my playlist.

A few times I have had a corrupted file and had to re-download. I noticed this happens most frequently when I am attempting to download a bunch of files at once, so I mostly try to download only 2-3 files at a time.

As a couple have also said, I don't do my own local backup, I view the GOG site as my backup :).

I always download everything right after purchase. If I want to play the game (which is often months later), I check if there is a new version that I've missed and in case there is, I download it again.

My stratagem as well. Though I only install when I'm ready to play, or want to examine the game contents.

Multi-terabyte internal and external drives are your friends, and the prices are entirely reasonable these days.

Current GOG backup folder is at 1.39TB and growing. I will need a new drive once linux versions arrive.

Mine isn't too bad at 744G, but I also have a lot of digital media of other kinds (music, books, movies). So my 3T internal drive is more than half full at the moment, and my 2T external is dedicated largely to that repository.

Just backed up my library unto an external HDD recently. As downloading it all took forever I'm now backing up all new games once purchased. Btw. really came to hate that GOG makes us download the whole installer for different languages again, that's time and harddrive space wasted imo. Hope more games will get those neat little language packs, that a few games already have, in the future. But that's probably wishful thinking on my part...

I have all of the 210 GOG games that I own on my HDD, with a few exceptions (like Kingdom: The Far Reaches, whose existence is evil) .

Back up EVERYTHING you might want to keep down the line. Trust me, you only have to lose all your data once for that lesson to stick. :/