I have yet again forgotten the formula, can someone remind me?
Is planetary attack included in the chance to invade?
The answer would be much helpful ^^

(Ships Attack /3) / (planets att+def) gives a odd of 1 of possibility, so 0.2 is 20%, 0.75 is 75% and so forth

ship total attack (including bonus weapons like Psi-Amps)/3 divided Planet attack x 0.6 + def (including spec structures : Lazuli pylons etc and legion bonus= percentage.