The “Wormhole” artifacts allow you to connect two celestial bodies, greatly reducing the distance between them. This effects both range & speed.
Each rarity of “Wormhole” will decrease the effective distance between the two celestial bodies by:
Common: 2x Rare: 4x Epic: 8x Legendary: 16x Mythic: 32x
Some important things to note are, firstly, unlike many of the other artifacts with unique functions, “Wormholes” can be activated & deactivated without being destroyed. However, they will be put on a 4 hour cooldown between activations. Secondly, if a player loses control of one of the connected celestial bodies, any attack which is in transit will not land. This means, any energy or silver which was being sent will be permanently lost. Finally, the Wormhole bonus applies to all moves made between the two celestial bodies - regardless of which planet it originates from!
This planet has a “Wormhole” linking it to another planet. Any moves made between these two planets will land quicker, and with decreased “distance decay” of energy, due to the wormhole ‘reducing’ the effective range between them both. This bonus applies to both planets.
In the Early game, “Wormholes” aren’t most effective, as quick expansion leads to celestial bodies becoming ‘outdated’ quickly. The 4 hour cooldown after use means that if you are going to use one in the early game, think carefully about what celestial bodies are going to be the best to link - maybe there is a higher level planet you will be conquering and the wormhole can be used to fill it quickly to aid in your expansion.
In the Mid-Late game, “Wormholes” (and a lot of them) can become invaluable. Having an empire intricately linked by Wormholes can allow even distant reaches of your empire to be either energy generating machines. Similarly, it means that you can sustain large, powerful planets (of high level, or with particular 2x Moons), even if you don’t have many planets directly nearby.
The details of how Wormhole interactions apply, and the distance reduction this rarity of artifact provides.
As you can see, these artifacts give an amazing buff. Being able to reduce the distance between your powerful celestial bodies will allow you to threaten players on many sides of your empire, and will make it difficult to overthrow your larger planets, due to the constant influx of reinforcement energy.
This image shows how DFDAO were able to setup their empire to sustain energy generation in far away parts of their expansive empire!