In this chapter we have described how to obtain chests and a complex reward system (by which you obtain them) for completing side missions. Knowing the cycle allows us to predict which chests we will get for additional missions of specific type.
There are several ways to obtain chests. Some of them will be given to you for completing the main storyline missions, completing the next floors of the Abyss mode and performing side missions. You can buy them in store for gems, which is the currency of in-game microtransactions. And so, while the missions of the main story or Abyss mode floors have predetermined types of chests as rewards, the randomly generated side missions reward us with a random chest... or at least the developers want us to think so.
In fact, after completing a side mission we get another chest from a list of 500 items invisible to the player. On this list, the order of the chest types was set in advance and although it requires some work, it's worth keeping a log of chest types that we have recently acquired. With a sequence of 4-5 chests, we can estimate where we are in the list.
Why you should do that? To know when a gold chest will emerge instead of wooden or silver one (38 cases out of 500), and even the elder one (2 cases out of 500). Remember that death or canceling a mission does not apply to the cycle. You can complete up to 100 side quests/missions a day.