Can someone explain how I should open the chests with lockpics? Easy ones, sometimes I get them open with luck, but mostly just waste lockpics since I clearly have not understood the idea how to open them

I have gotten it down somewhat. What I do is pay really close attention the tumblers. As they slide down their movement will become more rapid side to side. As soon as they start to wiggle (for lack of a better word) I let up. Sometimes it takes, other times it comes back up, but that gives a reference to the depth they need to go. Just takes some practice and a light touch. From my experience, it seems to be better if you let up a tad early so you don't force it and break the lock pick.

It took me a bit to figure it out as well, but you have it mostly correct.

The whole trick is to push the tumbler down till it starts to shake, as soon as that happens you let go. The easier the chest lock the longer you have to let go. On the harder chest you have to let go as soon as it starts shaking for it to be successful. The shake lets you know how far down the tumbler needs to be.

umm, so you press each of the 5 pins down slightly, and then it opens on it's own? Do you press the E/R button (something like force the lock) at all to succeed?

No it's just a matter of letting go right when a pin starts to shake, when you've gotten all pins in place the chest will unlock.

Force lock is a way to open it without having to do anything. If it says 10% next to force lock then you have a 10% chance of unlocking it, if it fails the lockpick breaks. You can pretty much ignore the force lock thing entirely.

You guys know you should hold down with left mouse and click with right mouse when they wiggle? (no chest is a Problem then)

Thank you all for help I'll try these tips next time. Maybe next chest won't need 20 lock pics to get it open

Didn't know that, just been using the wiggle/shake cues. Will give it a whirl later on and see if makes a difference.