What are some of the rules that are often over looked or missed in games?
I always forget about resisting knockdown, just off the top of my head
I’ve seen a lot of GMs note that they forget to remove one Momentum point at a scene change.
My players always forget to make use of their role abilities.
For the latter, I like to give each player a handout with the descriptions of their species Trait(s), role abilities, and Talents to keep with the character sheet. It’s a bit harder to forget if you’ve got the information right there and don’t have to look in the book.
I didn’t realise the players got 1 Determination every session.
I wondered why Values were being used so infrequently
That is a thing not few GMs tend to forget. Often you get 1 Determination per adventure, which might easily take three or four sessions. That has the consequence, that you only spend your rarest resource in extreme situations.
And getting a value compelled is another point quite a few GMs don’t do at all or very rarely.
I have extensive Fate gaming experience, so doing self-compels and as a GM compels for values in a negative way is rather common for me.
But I have played in games of nearly a dozen STA GMs, and a somewhat more frequent refresh or award of Determination a majority of those GMs don’t practice.
I’m not quite sure if it is a rule that is overlooked as much as there is some insecurity on the GM’s part how and when to refresh, how and when to award Determination. That requires getting acquainted with all those values your players might have. In a game with 6 or 7 players, you have 24 or 28 values to be aware of. That is hard (in Fate Core you usually have 5 Aspects per PC, but you have usually smaller groups of 4 or 5 players, STA groups tend to have a higher number of players - and work with a larger groups much better than Fate groups).