played a game but nothing unusual came up..
Strange, economic upturn (more credit income) and it's counterpart (less credit income for everyone) is common, occurs about once in an hour as I saw it, And instant rebellion is quite opften as well (you lose the planet immediately and a bunch of REBEL ships appear, even some capital ships, but only on planets you took from a currently dead player I guess).
There are moving things like the moving magnetic cloud doing the same as the stationary neutral thing, or the gamma ray burst that instakills the population of planets it touches.
There was once a coronal mass ejection, I guess it does the same as the Vasari superweapon without the phase node and the damage, shuts down structures for a lot of time.
I only played some fast test games and a complete game against AI, and have not seen the other events so far, and there are 11 of them.
I know that there are black holes, quasars and dense stars but the others I am unaware of.
You are wrong.. There is no quasar as it is a special galaxy generating extreme amounts of energy.. There is a neutron star, black hole and a pulsar, doing various random stuff but nothing special as you don't really fight within the star gravity well anyway..
