A black hole is one of the most dangerous expedition outcomes. Its default event weight is 4, which equals about 3.57% with the standard total weight of 112.
How does this expedition outcome work?
Once a Black Hole event is rolled, the default mechanic has a 12% chance to destroy the entire fleet. If total destruction does not happen, the event still removes roughly 30–95% of each ship type sent.
What are the default parameters?
This makes Black Hole very different from Nothing or Delay: even without total fleet loss, the result can be extremely expensive. The more valuable the fleet, the larger the real exposure.
What determines the result?
For that reason, maximizing rewards should not be the only goal when building an expedition fleet. A good composition should also be acceptable under a severe-loss scenario.
How should you use this in practice?
Negative expedition outcomes are drawn from the same event system as rewards. Sending a larger fleet can improve the potential of some rewards, but it also puts more units at risk when a damaging event occurs.
What should you watch out for?
An expedition should therefore balance potential reward against exposure. Do not send ships whose loss would cripple your account solely to maximize one reward parameter.
Related FAQ: How do pirate encounters work on expeditions? · How much can an expedition delay a fleet return?