Shards are one of those mysterious phenomena that we know generally what they are and what usually causes them, but we don’t know the exact mechanism behind it. Our main working hypothesis is that the sentient mana that makes up the universe (or perhaps even the Deities) has an imperfect memory which may break apart, creating a small pocket “world” or “dimension” which contains the memory fragment. Shards are usually created from some kind of dramatic event, which leads us to believe that it may be a defense mechanism, similar to the human psyche’s many defense mechanisms toward traumatic experiences.
However, not all Shards contain such terrible memories, so that’s clearly not 100% the case.
In either case, Shards generally come in two types: looping and non-looping. A looping shard will repeat the events that caused the Shard’s creation over and over, without end, until the Shard either heals on its own or is closed by some other means. The inhabitants will re-live the experiences as they happened at the time. For a mercy, they don’t seem to be aware of this fact. The non-looping variety are a sort of alternate timeline, which continues as if it were whole, though confined to the region of space which the Shard represents. This creates duplicate copies of the involved entities and persons, though they cannot leave the Shard. These Shard-people are imperfect, as if recalled by someone who only vaguely remembers them.
Outsiders can, however, venture into the Shards. Most Shards can be exited if you keep in mind where the rift you entered from is. However, some tend to be more hostile and actively trap wanderers inside. Procedure dictates that we check the entry rift’s stability before entering any Shard.
Rifts can be difficult to spot, especially if you don’t know what you’re looking for, and some may even open without warning around a person. Specialized equipment may detect small spacial fluctuations, and we make a habit of doing routine sweeps around areas that have seen significant turmoil, such as war zones or locales that have recently experienced deadly disease.
Thankfully, with good preparation and the appropriate powers present, Shards can be ‘healed.’ Many heal on their own over time, but especially stubborn ones may pose a threat to travelers wandering unknowingly through an area with a troubled past. These require direct intervention, one of our duties in healing Terra and keeping her safe.