Timeline

Overview
The timeline will have 4 segments:

Pre-Betrayal - Before the point at which Providence trapped Mithrix on the moon.

Post-Betrayal - After the point at which Providence trapped Mithrix on the moon.

Before Present - Before the events of the game take place, but are unknown if they happened before or after the Betrayal.

Present - During which Risk of Rain 1 and Risk of Rain 2 take place.

Pre-Betrayal

 * Mithrix and Providence (the brothers) somehow exist on Petrichor V, be it born or not.
 * The brothers chase glass frogs in the sun.


 * Providence catches Mithrix tossing worms into a gravity well.

- A few millennia pass from this point to the next -


 * The brothers create teleporters, which they call gates.
 * Mithrix learns that he loves design whilst Providence learns his ability to create and shape.
 * Mithrix builds the Bulwark's Ambry for Providence to create anything he wants with the 4 elements of the universe Mithrix found, and in which Providence makes the Artifacts.
 * The brothers, as they reshape the planet to how they like it, talk about Sundered Grove. Mithrix loves triangles, while Providence loves circles/rings. They both love trees, though.
 * The brothers start to create Golems, which they call Guardians.
 * Aurelionite is created, and Mithrix has to lock him away as he is sentient and dangerous to him and Providence. This is thanks to Providence adding too much soul than the design needed to Aurelionite, making them powerful and unstable.
 * Mithrix shows Providence how to create a golem with no soul, being the original design of the Lunar Chimera (Golem), which Providence then later used in making the Temple Guard.


 * Much time passed before "She" came. It is unknown who "She" is, but its known that she is no female that is known in Risk of Rain.
 * The brothers know that "She" is coming again soon, and Mithrix wants to show her some of the gates they've made.


 * Mithrix created the first, and only of its kind, teleporter that can travel between planets, which is known to be the Primordial Teleporter. He does this because he wants to find more of their own species and leave behind the planet, which has doomed species on it.


 * Providence, who cares for the beings on the planet, lets Mithrix go on ahead to the moon. Once Mithrix is there, he locks the way back, trapping Mithrix on the moon. We refer to this point as the Point of Betrayal.

Post-Betrayal

 * Monsters start to get taken by Providence from other planets to Petrichor V.
 * The Elder Lemurians, as a thanks to Providence whom they call their Hero, create the Temple of the Elders.


 * The Imps invade from the Red Plane, trying to retrieve an unknown artifact, but get trapped on Petrichor V thanks to Providence's physical presence.
 * The ancestors of the Grovetenders, as thanks to Providence for saving them from death, create Scorched Acres with their wisps.
 * She had came and died, giving her blessing to Providence. What the blessing was is unknown, but her sacrifice is unknown to the inhabitants of the planet. Mithrix resents Providence being given her gift.


 * Mithrix starts creating lunar items with help from others on the moon, the items then being scattered across Petrichor V for any being to find and become influenced by him, becoming his servants.
 * Mithrix tells his servants (primarily being the Twisted Scavengers) to go to the monolith in A Moment, Fractured, and to use it while holding his beads. It sends them to A Moment, Whole, a place safe from the coming tidal wave of his vengeance, where they can experience peace.
 * Providence, to try and stop his brother, hunts down any that find these items. Any and all lunar items found get put into Cleansing Pools and turned into Pearls.


 * Mithrix designs and builds the Lunar Chimera (Wisp) (inspired by the Greater Wisps and Clay Templars) and the Lunar Chimera (Exploder).
 * Mithrix details his plans for getting back at his brother who betrayed him, noticing Earth and planning on destroying it by building a Grander Teleporter to get there, all to see the look on Providence's face.

Before Present

 * The War of 2019 takes place, otherwise known as the War of Slopes. It is stated to be the bloodiest conflict in human history. Artifacts such as the Berzerker's Pauldron and War Horn are retrieved from the site of the battle.
 * The High Court becomes the most technologically advanced society known to humankind, keeping their advancements a close secret. The House Beyond travels deeper into space than the rest of the Court.
 * An Artificer of the High Court somehow gets trapped by Newt - or more likely, by the dark powers that influence it - in the Bazaar Between Time.
 * Fireworks are re-legalized for residential use in 2054, having been banned previously after terrorists disguised missiles as fireworks.
 * The Followers of N'kuhana grow in popularity, a cult that is fully devoted to Her Concepts. In one particular instance, a ritual sacrifice by them is stopped by a boy who attempted to save his sister. The dagger they used ends up on the UES Contact Light.

Present

 * The UES Contact Light goes off its scheduled course to take a detour through an unknown star system. The detour was requested by an unknown individual, redacted from the blackbox data.
 * On Day 5 of their detour, the UES Contact Light discovers Petrichor V and begins studying the planet. Coordinates are marked and xenoarchaeologists and Engineers are sent down to the surface.
 * After having been around Petrichor V for roughly 35 minutes, the xenoarchaelogists and Engineers discover a teleporter. Hoping to find a matching pair, they load the collected teleporter into the cargo bay. It is unknown how they got it aboard.
 * About 25 minutes after taking the teleporter, Providence then appears onboard via the teleporter, smashing the ship and causing it to crash in the span of 4 hours. At some point during those 4 hours, Kur-skan the Heretic appears on the ship via a blue portal, rushing to the front to repair the ship so it can fly, so she would be able to escape. She failed doing so, as Providence appeared behind her as she reached the bridge and killed her instantly.
 * The ship spilled its contents across the entire planet and into space around it, some managing to stay in its cargo bays, with any survivors evacuating the ship via escape pods to the planet below. Only 56% of the escape pods were launched before Providence presumably killed the rest of the crew aboard.
 * Out of the escape pods that shot out of the ship, one contained the Commando from the first game, aka The Survivor. The rest contained the surviving crew of the Contact Light, who established Rallypoints for survival and reconnaissance such as Rallypoint Delta.
 * The Survivor, in the span of a few weeks, traveled through the teleporters to reach the remains of the UES:CL. He documented his time on the planet via the monster logs and some item logs, the items he found being classified as field-found. Along the way, he frees Acrid from its cage in Sunken Tombs.
 * The Survivor battles and kills Providence, and uses the still functional components of the UES:CL to escape the planet. The Survivor is also the only survivor to escape. Acrid, instead of escaping, was at some point captured by the Void Reavers and detained in the Void Fields.
 * The survivors Marion, Pugh, Larsen, Dillon, Carney, Stevens, and Hitchcock end up in the Wetland Aspect. Hitchcock is killed by Stone Golems. To escape the Golems, Marion gives the dagger she had in her backpack to an unnamed survivor, who kills her with it and manages to stop the Golems with its power. Carney later discovers a book in a chest nearby called the N'tormat, which describes N'kuhana's cult. The unnamed survivor becomes corrupted by N'kuhana's influence and murders the other survivors, sacrificing Carney to the altar they built in the cliffs below.


 * The rest of the survivors die out over time, meeting grisly fates all across the planet. Acrid survives his imprisonment in the Void Fields, setting him up to return for the events of the second game. He is the only survivor to appear in both games.

- An unknown period of time later -


 * UES [Redacted] responds to the distress call of the UES:CL. The ship is well-equipped, with units designed for exploration, science, hydroponics, and more.
 * Members of the UES [R] go across the planet to explore, document monsters, environments, retrieve Security Chests of the UES:CL, and other things.
 * Some scientists on UES [R] find the Artifact Teleporter on Sky Meadows, leading to the Bulwark Ambry, and successfully manage to connect to it using their technology.
 * Other scientists dissect monster parts, while exploration groups bring in artifacts and materials from the planet that can be studied.
 * During their time around the planet, REX breaks protocol and becomes sentient. The head of the Hydroponics division tells the hydroponics team, who have grown fond of REX, to "terminate the unit". Judging by the fact that REX is later found intact on the planet's surface, it can be presumed that the team chose instead to jettison REX from the ship, solving the safety issue but leaving their new friend 'alive'. REX eventually runs out of fuel and powers down, alone in the Abyssal Depths.


 * It is entirely unknown whether the crew of the UES [R] went back to where they came, or died on the planet.

- An unknown period of time later -


 * UESC re-hires a famous retired Captain, who worked on many secret projects for them before, for one last mission. He agrees, but is suspicious of the pretense of it being a "rescue mission" but having been assigned the UES Safe Travels, which is not a rescue ship. As a precaution, he asks the ship to be filled with armaments and supplies.
 * Various mercenaries are sought out and hired for the expedition, including bounty hunters such as the Huntress, and the Commando - a different commando from that in the original game - who is reassigned from active duty elsewhere.
 * Before the UES:ST takes off, the Bandit sneaks aboard, hoping to use the rescue efforts as cover to steal from the many security chests dropped by the Contact Light. In a private conversation with a friend, he mentions certain other thieves, likely other members of some sort of group or guild, who snuck aboard the Contact Light before its fateful crash. Due to the many mysteries surrounding the Contact Light, some of these thieves may have had secret missions or ulterior motives. But this Bandit is only there for the loot, much like his predecessor in the original game (whose intentions can be inferred from his victory text).
 * Hiroshi and Rico, maintenance crew and part of UESC, kill time by modifying a MUL-T unit inside of a hangar and enabling its learning module. Though originally intending to disable said module after having their fun, they fail to do so.
 * The UES:ST arrives in orbit of Petrichor V, recieving the distress signal the UES:CL sent out during its crash. The Captain sends various members of the crew down to the surface, with unique individuals - including himself - landing in drop pods and more typical groups touching down in rescue ships.
 * During the first twenty-four hours, major casualties are sustained. Many of the the rescue ships crash or are destroyed on the surface by the planet's inhabitants. An unknown number of survivors make their way through the planet's various teleporters, eventually taking a one-way trip to the moon.
 * Once on the moon, the survivor(s) discover a rescue shuttle that has been captured by Mithrix and placed under a forcefield, with evidence of a struggle having taken place; a number of dead Commandos can be found around it.
 * The survivor(s) battle and kill Mithrix, which frees the rescue shuttle. Immediately upon Mithrix's Death, Void Reavers invade the moon.
 * The survivor(s) escape in the rescue shuttle.
 * Mere moments later, the Void Reavers teleport the entire unfathomable bulk of the moon to another location - possibly the Void Fields - for containment. The Reavers may see Mithrix's death as an opportunity to seize his assets, to take them for themselves or to keep them safe from others. They might instead be seeking his body, to imprison or even reanimate it as part of some inscrutable agenda. Or, they might be trying to prevent some localized disaster resulting from the untimely end of the realm's lord and master; a disaster heralded by the sudden, sporadic bursts of energy unleashed across the moon's surface. They may be driven by any or none of these purposes. The true motivations of the Void Reavers are, after all, unknown. For now.