Clash of Clans Guide

Part 4- Bade Defence Basics

Base Defense Basics
Basic elements of strategy and good base design. Rules of thumb for designing your first base.
How to Defend your Defenses
Average Decent Best

Enemies spawning in this orange area will auto-attack the archer tower right away! Eight archers or so will easily kill this turret. Enemies have to spawn outside of this green box, and can't immediately attack the turret. An archer placed at the blue dot will attack the buildings in the order seen.
Walls are good, but are not the only part in a super awesome base. The #1 mistake I see new players (or not so new players) doing is placing their defenses so they can be targeted by archers spawning outside of the walls. Don't make this mistake.
The difference between 'Decent' and 'Great' has to do with the way units decide which building to attack next. It is too complicated to get into here (this 'basics' section) but I think I'll cover it later in more detail. The buildings protecting your defenses do matter - Mines/collectors will have more HP than Barracks/Builder's Huts.

Oh Gosh! Enemies Can Spawn There Too?!
Not good! Unless it's your enemy!

Yes, enemies can spawn around the ring of your base. No, you can't build there to stop them.
Holes in bases are bad, mmk?
When you move any building or wall (but not decorations), it shows you white lines one space larger in every direction from that building. This is showing you where enemies can spawn. Make sure you don't have any holes in your base to let them spawn inside your walls. That would be bad. I will write about how to leave intentional spawn spots in your base later, in the advanced base defense chapter.
Overlapping Defenses
Another common mistake: placing all of your defenses widely spread apart, to cover as many buildings as possible. Dies very easily to several giants. Or to groups of infantry, especially archers. Or to balloons. Which I guess means it just dies to everything.
This often goes along with trying to stuff everything inside your walls, covered later.
Splash Damage: It's your friend!
Mortars (and later Wizard Towers) are your first and last line of defense against mass infantry attacks. A mortar's damage is only limited by how many troops your enemy puts down and how well you funnel them into where you want them. A fully upgraded mortar (level 8, total cost 12,560,000 gold) will do 65 damage in one shot to the units within the splash zone. In the same amount of time (5 seconds) an Archer Tower (level 1, total cost 1,000 gold) will do 55 damage to the unit it is targeting. What does this mean? It means you need to make sure your splash damage defenses are hitting enemies in groups and are protected. How do you get them to hit enemies in groups? Put them in the middle of your base - As soon as the enemy destroys a wall and funnels through it, they will be nice and bunched up for the mortars.
Where should I place my Mortar?
Somewhere very protected. Probably in the middle of your base, ideally with its own wall around it for the mortar is unable to attack at close range.
Where should I place my Air Defense?
In the middle of your base. Mass air attacks are rare (due to time to train), but not unheard of. A single, upgraded Air Defense is a wonderful deterrent, but it should be placed in the middle of your base. More specifically, it should be placed such that, if a mass balloon attack comes, It won't be the first, second, or third defense they kill.
Don't try to stuff everything inside your walls
As a counterpoint to Overlapping Defenses, don't try to enclose everything within your walls. First off you will often break Overlapping Defenses and Defend your Defenses by trying to cover everything, but secondly it is just a waste of walls. Double thick walls are better than a massive single thick wall.
What should I keep outside my walls?
Absolutely keep your Builder's Huts, Laboratory, Barracks, Army Camps and Spell Factory outside your walls. None of these matter if they get destroyed - no progress or resources are lost. Next, I would keep out Gold Mines and Elixir Collectors. Each of these has some consequence if they get attacked: Mines and Collectors can have resources stolen (but only uncollected resources). Some people really like keeping Mines/Collectors inside - It depends on how often you play. If you do keep any inside, make sure they are your highest-level units.
What does that leave? Town Hall, defenses, Elixir Storage, Gold Storage. All of these should be inside your walls, and as well-protected as possible. If you are at a stage in the game where you don't care about trophies, you can also kick your Town Hall outside the walls. You will be easy to defeat, but if you're only trying to protect your resources, the Town Hall takes up a lot of space.

Is making the base square or rectangle hard for other players?
No, it's not. I personally find bases with square or rectangle bases easy to destroy, because there aren't any extra walls that are going to be the obstacles in my way. One or two wall breaker can easily breach through. If you have extra walls, use them for making it more difficult for players. You should put your base into a maze or with lots of layers. Wall breakers will also go for walls that are connected with at least three other walls. This means placing walls that stick out of the perimeter will be focused first.