One attempt is usually for feats that require doing something x amount of times in one go. 1st attempt is a feat you only have one shot at doing durring the instance, if you fail you have to run the entire instance again.
First means it needs to be your first attempt. If you fail the whole instance must be reset. One means that you need to do whatever you need to do in that one go. Let's say you had to pick something up 10 times. You can't do 6, wipe and then do another 4. That would be two attempts. You would need to do 10 in one attempt for the feat to count.
Means you have to do it in that instance on the 1st try without a wipe. It doesn't mean you can never try again, it just means during that moment of playing the instance. Didn't make it on the 1st attempt then finish the instance and try again from the beginning of the instance the next time you play it. I know it seems like they are 2 different meanings the way they are used in descriptions but they are saying the same thing.
I'm not certain what your looking for. Did you get a message in game about one or both? generically a first attempt would be the first ever time you tried something.. or the first try on something that day, that week, or that mission. ONE attempt would mean, putting it into terms that might appear in game. You were able to defeat the Boss and accomplish all objectives in one attempt.. meaning no team wipes. Obviously depending on what ever feat or ?? we are referring to its very possible that the first attempt could also be the ONLY attempt and it would seem to me that would apply to just about anything we are talking about in game. Now using a generic definition you could complete something in one attempt but if you had already done that same thing 20 other times on other days. it wouldn't be your first ever attempt. Like I said I can not think of any feat or any thing that the game requires
