The invasion system is a mechanic in Wyrms of Nyrus that features a scheduled and semi-random series of events that progress in difficulty as Wyrms gain Invasion Points (InP). All events will select a random player that is currently on the server, and will always target a lone player in singleplayer or a server that only has one player present. The invasion system will never run when there are no players on the server.
The Nightmare Begins
By default, as of v0.5, the invasion system begins on or some time after the night of Day 21 on Classic. These values can be tweaked in the configuration files, and the system can be changed to take place right at that date, or at a random chance each day.
In versions before 0.1.4, the invasion starts at a random chance per second, about 0.00001%, without rolling per day.
When the invasion begins, the players will hear an auditory warning, and the Visitor will spawn right above them, causing a flash of light. This marks the beginning of the invasion.
If no players are on the server, the event will not take place until someone logs in.
The Visitor
The Visitor is the very first Wyrm players will encounter. It is the largest Wyrm in the mod, being a voidwyrm. It holds a large health pool, but like all wyrms, is weak to fire. It does not have any damage reduction stats, so arrows, potions, and status effects can easily take down the Visitor.
Until the Visitor is killed, it will continue to spawn 2 to 5 drop pods every ~3 minutes, give or take. It can drop Hexe Pods or Callous Lander Pods.
As of 0.2.1, The Visitor is considered a boss in the game and causes the nearby player(s) to see a yellow health bar. Use of ranged weapons is highly recommended to take it down, just beware of the Callous Pods that may drop down onto the player.
Pre- Visitor Update
In older versions of the mod, Visitors are invulnerable¸ despawn after a set amount of time, and cause a Hexe Pod to fall from the sky immediately.
Visitors had a much smaller model and different animations before v0.1.4's release.
Random events
Once the Visitor arrives, the world is now permanently locked into the invasion, and can only be reverted using cheats. Events may cause drop pods to land onto the ground at random, spawning units like Wyrmlings and Probers.
As of v0.5, events are now staged, having both beginning and ending stages, along with any number of middle stages. Each invasion stage’s event pool can be modified by the user.
After the wyrms gain InP, invasion stages progress into more severe events, such as the appearance of the Hive Creep and the associated Creepwyrms.
At this moment, there is no way to reverse invasion stages. Players can slow down the invasion progress by killing wyrms, containing Hive Creep spread, and, most effectively, killing Probers. Killing wyrms, however, has the cost of adding Evolution Points (EvoP) in exchange.
Invasion events will not take place if there are no players on the server.