This was supposed to go up at 12:00am but I messed up. Whoops!
I've been GMing L5R a whole heck of a lot over the past 5-7 years. Yesterday for the first time in months I picked up my base book for 4th ed and read through some of the mechanics sections. Funny enough, I found several things that I've been doing wrong. Small things mostly, things that were changed from previous editions, but still errors. Errors that in some cases have made things harder for my players - or my NPCs - and errors that in other cases have made things easier.
Ultimately, I don't care too much. The sessoins we had were fun and the rulings were consistent, but it is not unusual for this to happen. The way we remember things gets clouded by earlier editions, earlier rulings, or on the spot judgements. With games we aren't as familiar with it can happen even more.
Because of this I try to make a point of going through my core books every few sessions and looking for things. The GM section is a particular favorite place for me to go, because it often has ideas and thoughts on how to give the feeling the game designers were intending when they made the game. That feeling is important, because it is often what the rules are made to help carry out. Trying to run a Horror game with Mutants and Masterminds is possible, but trust me when I say you'll have a much better time conveying a lot of the feel with a game designed to handle the horrific like Unknown Armies or World of Darkness.
For games I'm not as intimate with I try to do it more often. Yesterday, after putting the L5R book down I picked up a copy of Edge of the Empire for ideas for my Star Wars game.
The biggest take away? Fear Checks are a big part of the Star Wars experience. The rules for Fear Checks and reasons for them are in all three core books (Edge of the Empire, Age of Rebellion, and Force and Destiny.) They become even more important in Force and Destiny where a failed fear check can also generate conflict and push characters towards the dark side.
I also learned that I shouldn't be knocking characters prone for anything less than a triumph and a character that has a specific talent in combat, because that is what it takes for an attack to knock someone prone.
Finally, in reading through the Strain section I was reminded that strain is more than just mental stress or physical bumps and bruises but a combination of both. It's a way of attacking a character with more superficial wounds, or adding a cost to near failures. This gives me the choice to present options. A character who grabs a ledge to avoid falling could end up with three strain from a wrenched shoulder, or could take a setback die on all actions involving that arm for the remainder of the scene for the same reasons.
Do these things impact the previous sessions? No, not really. But going forward they are things I need to work on including. If nothing else, they give more tools and options to put the PCs in the situations I want the PCs in.
If you have some free time maybe grab that gamebook for the system you're running because you know it frontwards and backwards. Read some of the mechanics and the GM section. You might just surprise yourself.
Edit: I accidentally a paragraph.