I’m playing in this very enjoyable game and had a situation where I wondered if there is a bug in the combat code …but turns out not to be the case - but since I was confused, thought I’d document here. The players were nice enough to send me their event logs and reconstruction of what happened so I could investigate.
As sometimes happens, Player 1 (P1) and P2 attacked and landed at the same star defended by P3.
P1 attacked with 167 ships and had W6 - came form 4.976LY and so was 0.310 on last tick
P2 attacked with 74 ships and had W5 - came from 4.090LY and so was 0.090 on last tick
P3 defended with 173 ships and had W6.
IF P1 and P2 had been aligned, then I would have expected BOTH to get “upgraded” to the highest Weapons level and both attack at W6 … with P3 defending at W7 after getting defensive bonus. Since they have enough ship to win, then the player with the most ships (P1 here) would own the star with the other ally (P2) hanging out there.
However, they were NOT aligned (FA is not even turned on in this game). So I thought there would be a round-robin fight, each at their own respective weapons level … which I think (?) was originally how NP worked (before formal alliances) and how it was documented. But it’s been a long time since I looked at the Combat Help Page so maybe the wording changed - here’s what it currently says:
## More than 2 Players
In combats that involve more than two players, the players are arranged into teams. The Defenders are all players in a formal alliance with the star owner. The Attackers are all other players.
All ships fight with the best weapon skill of their team. The entire defending team will receive +1 weapons tech.
The battle is resolved as above, but if the attacking team wins, the star is given to the player who has the most ships in orbit AND THEY BECOME THE DEFENDER (GETTING THE +1 BONUS) IF THERE IS A SUBSEQUENT BATTLE.
If, after the star has given to the largest player, there are ships in orbit who are not allied with the new star owner, another combat will begin. This continues until all players at a star are in a formal alliance with each other, or only one player remains.
And what happened in the initial battle is exactly that. Both P1 & P2 fought at W6 (so P2 got “upgraded” to P1’s weapons level even though not aligned) and they won the battle.
So P3 is gone … but P1 has 27 ships left and P2 has 11 ships left.
P2 came from a closer distance (both total and last tick) … so I thought that they would then defend.
But that’s NOT what happened - P1 got the defender bonus.
I just tested this (LOL good thing I used super-easy to remember passwords for my test accounts from years ago when we were figuring out formal alliance interactions) and yea, the player with the MOST ships leftover from the first battle becomes the defender in the secondary one.
I actually had a 3-way going on … so the defender then changed again for the tertiary battle … to the (new) player who had the most ships … NOT who was “closest”
I actually think this makes sense - the player who brought the most ships to the battle (which was mutually won) then get to be the defender. Note to self: Send more ships, use the other person’s weapons to win mutually, and then get defender bonus against them! 
Note that if the star is unoccupied, then the closest gets the defender bonus.
I was initially puzzled by this … but again think the behavior is “correct” … and if you read the documentation carefully, it does say this. But figured I’d post here for others as an FYI.