I Don't Understand Battle Memory

[Symbeorn]

How do I use this? Does it just store the gambit for later, or does it use the gambit right then and also store it? For the life of me, I can't understand how this skill is supposed to be useful. I've searched around, but a lot of what has been written about this game/class is pretty antiquated. Thankful for any advice!

[Altair6]

Uses it and stores it.

So. Open battle memory by using improved Deft Strike, for example, and build a gambit, use it and it executes and also gets stored for later use without having to build it.

I sometimes use it to store an interrupt skill if I know the mob(s) use stuns. Probably not the best use but it's an example.

[Vilda]

Store interupt gambit here is perfectly fine. It can be used also for emergency heal like restoration or for big damage gambit like desolation and so on.

and the use is:

use double builder gambit: spear+spear or shield+shield or taunt+taunt
you get a buff (the white symbol around your character) called Potency
now you use any gambit you want and it is stored in battle memory, the buff Potency is consumed
now you can use the stored gambit from battle memory with single button

[scorrp10]

Yeah my '-' key is set to Battle Memory.
When you do a 'double' gambit (almost always shield+shield for me, or spear + spear when in ranged stance) is primes BM.
Then next gambit done is saved to BM in addition to doing its usual thing.
In most cases, it will be some 5-step gambit like Conviction or Desolation so I do not have to build the whole thing next time I need it. Or if fighting a mob that has nasty inductions, I would store Boot or Onslaught. Or Shield Tactics if I anticipate stuns.
Once you save gambit to BM its icon changes to that gambit icon. Then when you need, you can fire off that gambit again with a single keypress/click.

If you already have a gambit in BM, it will not be replaced by another if you do another double. You first need to fire off the saved gambit.
BM will auto-clear if out of combat for 15(?) sec.

[Pavlin]

How do I use this? Does it just store the gambit for later, or does it use the gambit right then and also store it? For the life of me, I can't understand how this skill is supposed to be useful. I've searched around, but a lot of what has been written about this game/class is pretty antiquated. Thankful for any advice!

Lets say it like this. When you start a fight with a boss/mob you know you will need to interupt you start with battle memory then use interupt gambit/ in this way gambit is stored in your battle memory and you can activate it without need to build it.
Outside that you can use it for storing 5 line gambits or some range agro grabing one/ when you know adds will spawn soon and you need to agro them. This give you freedon to freely use your gambit masteries without reason to wory you will need to hard build gambits at the last moment.
With 2 words - expirience/practice.
Good luck.