Ground target
Fast ground targeting just skips the green circle AoE targeting and large arrow pointing that you get for some skills such as engi grenades, most non-dagger elementalist skills, warrior greatsword whirlwind, etc. Playing with or without this is really personal preference and is more useful to some professions or in some situations than others.
There’s an option called “Disable Area of Effect Rings” on the first panel of the Options menu. DO NOT have that selected. It sounds like you might have it selected right now.
“Fast ground target” disables the circle that shows where YOUR aoe ability with go. If you have that turned on, turn it off for better control of your own aoe skills.
Enemy aoe abilities that target a specific spot on the ground should always show. However, some aoe attacks are just direct attacks that have an aoe component. Those don’t have a ground circles because they typically track and follow you. The only way to avoid those is to watch for the projectile and use the dodge mechanic.
Personally, I would like to know if there is a keybind to toggle Fast Ground Targeting on the fly.
Since that option is NOT in the key binding list, I doubt it’s toggleable via a key.
I have also heard of specific video cards that can disable this with a setting outside of GW2, but I have no idea of the details. It is also possibly a driver issue with your video card (which could be related to the outside of GW2 setting). The first thing to check is the setting mentioned above “Disable Area of Effect Rings”.
We go out in the world and take our chances
Fate is just the weight of circumstances
That’s the way that lady luck dances
Fate is just the weight of circumstances
That’s the way that lady luck dances