Weapon Cases are a kind of item in Critical Ops that when opened by a player, it will offer them a random weapon skin or a cosmetic knife. Each weapon case costs 200 credits.
To obtain weapon cases, one must have at least 200 credits, which can open one case. For every case opened, the player will be offered a random skin for a random weapon, or in a rare chance, a cosmetic knife.
A free case is offered in the Tutorial for new accounts which have not been previously used to play the game.
Sometimes, cases can be rewarded by entering contests. Example:
On May 11, 2017 Critical Force Entertainment initiated a Mother's Day challenge that ended on May 16, to where players would send videos or pictures of their mother figures and tell them how they thought of the game. The top posts were rewarded with weapon cases.