Don't put defenders in Empires & Allies

[Raja Ram]

This will make sure that when somebody invades part of your empire that is undefended, and let say your farms or other resources, they will just have two defenders to deal with. Usually, attackers/invaders would just use the minimal amount of units to invade. So, while they see two units, they use 3 units to counter the defenders. This is beneficial because it will be easy for us to defend our land, and get more resources out it. As well, I noticed that if you keep level 1 units (cadets, canons etc), and somebody attacks an undefended territory, then the level 1 units will become the default defenders (please correct me if I'm wrong here).

[Adonis]

If you don't have an inch in your empire that is undefended, chances are all invaders will use 5 units to ensure that their invasion will be successful. Now, if they use five units to invade, and you want to repel them, you will use a LOT of energy to repel the invasion and will likely lose units (although you will get resources if you've successfully repelled them). Anyway, the gist is, you will be saving ENERGY if you have lesser invading units to deal with.

[MacIntel]

If someone did that to me, I would become very annoying very fast. I'd return the favor using my best units and convince others to help out. Then I would redesign my defenses and no longer leave easy attack areas for you to hit. Then you'd lose units attacking me and defending yourself. You really don't lose much by getting kicked out and re-invading. If they kick you out immediately you wouldn’t even notice a time difference as you can attack or collect every 4 hours. The biggest trouble would be energy, but a 2 on 2 invasion usually only costs me a net of 3 or 4 energy at most.

[Common]

It really is just a matter of style of play. Some like to level up quickly and certainly the method described is a very efficient way of accomplishing it. Others want a fighting challenge and therefore will defend their empire with the best they can build. Zynga will soon put a end to no units empires cause this game is build for Defending your empire. Some are a little bit of both. Bottom line: Play in a manner that maximizes your enjoyment.

[desilva]

I've been using this "no defender" tactics for the past few days in order to 1. Welcome invades 2. Save some spaces and most of my farming’s are running the longest duration possible. As a result, I got a lot of invades/repels while helping friends to get easy resources. When you stack up 4 Ore Mills and 4 Ore Mill IIs, that's easy 60 Ores for your friends per invade, they'll get more if they come back in 4 hours to collect more Ores and black hearts. I am on level 30 and ahead of most of my friends and that's why I'm currently employing this tactic.

[RyanInt]

I'm keeping units deployed but I have "attack zones" that are undefended. I usually leave a block of farms, mills, and mines undefended. I let the neighbors occupy it until it is repelled by a neighbor or they turn on neutrality. What's fun to see about this No Defender tactic is that my ore mines, farms and sawmills has become a battleground of sorts. When I log-in, I always see 3 invaders and 3 people helping me out expel them. So, I don’t have any problems shooing away the invaders because I have a lot of friends doing it for me and they are getting resources out of it as well.

[AZUL]

This kind of makes you a boring neighbor. Why should you be able to get resources from attacking your neighbor, but they can't get the same from attacking you? It's just a game, and really, you aren't losing all that much in an attack except some energy and maybe a tank, soldier, ship, etc. I have been neutral twice. Once for a quest, and once when I had to build up my offense. A neighbor who is ALWAYS neutral is not a neighbor I want to help, send gifts too, etc.

[RockOn]

I disagree with the OP somewhat. Simply because, the way I make most of my coins is through huge "bonus click chains". The best way to get a big stream of clicks is to be fighting 5 of the same class enemy of the highest health you can fight without losing a unit. I often see people going after the cluster of 4 government buildings for the 2k coin loot and 8 possible click bonuses. I would rather go after the 9 small block clusters for the max 900 coin loot (or resources) and 18 click bonuses.