When I interactive with many cases/crates on the streets, it always says I don't have arm 101 skills? what is it and where I could get it?

Those are cases with tier 2 arms crafting component, you need to reach at least lvl 90 of crafting and be at least lvl 11 to be able to buy the next tier unlock(from any arms trainer) so you can get your max crafting level to 200, then you need to lvl your crafting over 101 in order to open those cases.

Originally posted by gandales

Those are cases with tier 2 arms crafting component, you need to reach at least lvl 90 of crafting and be at least lvl 11 to be able to buy the next tier unlock(from any arms trainer) so you can get your max crafting level to 200, then you need to lvl your crafting over 101 in order to open those cases.

can I keep crafting the same itme over and over for gaing lvl?

Originally posted by zollen

Originally posted by gandales

Those are cases with tier 2 arms crafting component, you need to reach at least lvl 90 of crafting and be at least lvl 11 to be able to buy the next tier unlock(from any arms trainer) so you can get your max crafting level to 200, then you need to lvl your crafting over 101 in order to open those cases.

can I keep crafting the same itme over and over for gaing lvl?

You gain lvls in crafting mainly from research(decomposing items) and opening crafting boxes, my advice is to research items adding items for each try until you reach at least 1/5 of research lvl that means that you will get lvls in crafting. The components you obtain from research you can use it to craft items for further research.

Yeah it's kind of an un-intuitive system at first, from the point of view of most crafting systems - you get more crafting xp from breaking things down than from making them! e.g. you get 1 point for making something, but you then immediately break it down and get many more points. 

However it only works fast like this in the early stages, there are diminishing returns eventually, whereby the items you break down have to be green or blue for you to get any decent crafting points for breaking them down.  At that stage, your main fast crafting xp income comes from researching green or blue drops (so it become a choice - sell on auction or break down?).

It kind of vaguely fits with the superhero thing though - you learn a lot from researching alien artefacts, etc. :)

I actually like the crafting system in CO precisely because I'm not a huge crafter - unlike most of my toons in other MMOs, all my CO toons have crafting at max, because it's easy to do so in the course of normal play.  Most crafting in MMOs is more like a major separate minigame, in CO it's just a little alternative sideline minigame, which I like - but I can understand why hardcore crafters wouldn't enjoy it much.

I also love the naming conventions for the things in the CO crafting system, sometimes it comes up with hilarious combinations.  OTOH, others seem to hate the naming conventions.

How do I break down item?

"Research" at crafting table.