Where you are in the tech tree is the only determining factor in merges. Neighborhood merging is flat only in that it pertains to research. So if your Terrace Farm is plundered the attacker has a chance at 10 free forge points. Atlantis Museum - This building gives you a chance to double the resources you plunder, including forge points.Voyager V1 - The first three times you plunder a building you get three random goods of that building's age.There are also two Great Buildings(GB) which are an incentive to plunder, one relates to goods, the other to goods or forge points. There are other reasons but not as common as those such as being in an enemy guild, revenge, just likes fighting etc. Some just care about one or the other, or a combination of battle points and goods or forge points(fp's). There are three main reasons why you are attacked. Guild(GvG) about two years later then Guild Expedition(GE or GEx) Championships two years after that, attacking and plundering thy neighbor remains part of the game to this day. And though the game had moved on to Guild v. Player(PvP) if you will though you fight their AI so it's not truly PvP. Forge of Empires(FoE) began in April 2012 exclusivity as a game based on competition and plundering between neighbors or Player v.

Forge of empires town hall plunder