I don't know. Most games I have seen start out peaceful. But eventually all hell breaks loose.
Diplomacy is very important not only in the beginning but all through the game.
In one game I was about to be eliminated from only Diplomacy saved my butt. I am still in that game while empires much larger than mine crumble all around me. I am in Last place (as I have been in most of the game) but still surviving.
I have been an honest ally and I believe it is appreciated buy the other players.
PBW is still fairly new. I know players that would make a Klingon proud in PBEM games go ultra-cautious in PBW. In time I think that will change.
Has anyone tried the 'take out my 1st neighbor' strategy on PBW? How did it go? I think it would work.
