One of the things that both Videogames and RPGs do a lot of is release post-launch updates for their game. Now, with videogames this comes in the forms of patches, dlc, and occasionally free content. With RPGs the options are a bit more limited, but you still get FAQs, Errata, and new books that expand upon the existing game. For today, I want to look at some of the pros (and pitfalls) for each of these.
On the off chance you don't know what a FAQ is, I'll explain it. A FAQ is a list of Frequently Asked Questions, along with their various answers. These are generally used as a quick stop-gap to fix issues with clarity. Things like "The rules say that ties go to the defender on page 70, but that players always win ties on page 85. Which is true?" The FAQ would then explain the situation and how it was meant (i.e. a player always wins ties, but between two players whoever is defending wins.)
FAQs are great, but suffer from the same problem that errata can have. Namely, that not everyone is going to know they exist. Sure, the hard core fans will know about them - and maybe even use them - but the new people to your game aren't. Because of this, you can't use a FAQ with the patch mentality that many game companies have now because you simply can't expect it to get to most people that are having a problem.
Errata is kind of like a FAQ on steroids. It not only addresses frequently asked questions, but can also change some rules and fix other issues that are in the book. This is frequently done to address typos that are otherwise clear (i.e. "the book says it costs 15 points for x ammo, but it should actually be 150 points.") These can be good for fixing up any major problems, especially balance issues or "feel breaking" problems that hit your game after launch. Trust me, these will come up. Nothing you do can prepare for a couple hundred people playing your game. Someone will find something that shouldn't be there.
The problems here are the same as with FAQs in that people aren't always going to get them. Also, some people will just flat out dislike some of the changes being made. I know my group has disliked a bunch of the changes made in the Deathwatch errata. Not to say they're "bad" changes, but we preferred the rules how they were in the book. The other problem errata can have is when it needs its own errata. This just starts to make things look bad when the fix you released simply causes more problems. Errata should never be considered a quick patch job. Ever.
New Books are probably the favorite of the industry to use. Why? because new books bring in new money. This is also where you're going to see the most true expansion to your system. New classes, new races, new equipment, etc, etc. This is less like a patch and more like one of the old expansions for games of old. Sure it was the same game, but you had all new shinies to play with and a new set of adventures. This is one of the areas where some companies thrive, while others start to fall apart.
The various pitfalls for new books are similar to other things, and a lot of them are Quality of Life issues. Often a game will power spiral through these books (things will just get more and more powerful as the game goes on.) This is actually fairly natural since the developers want something new and cool to wow new players with, and then later have to "beat out" the last cool thing they did. However, when doing these things you need to remember that these new rules have to play nice with the old ones too. Unless you are just trying to invalidate old content anyhow. Other issues can come from the fact that sometimes new books will also need their own FAQs and Errata. This is, sadly, something that just happens with the printing/writing process and a release into the public.
Still, new books do bring a lot of good. Just, if you're making one, try to make sure it plays nice (and by nice I mean in a PVP fight doesn't give one person a huge advantage) with the core system. After all, often times the core system is what folks wanted to play...and that includes power level.