- A turret sight registration, from now you must place turret on flat surface with clear sight of the enemy
- An archer sight registration, from now you must place archer where they can clearly see the enemy, not through weird shaped window, pole, etc

I made youtube videos about this guide

Best Defense Design :
(Was made in Hard mode, only 2 Engineer,so that's very lethal defense)
(Video above made in Normal mode, take 2 minute to clear all the enemy while this one only take 1 minute)

Archers is the best defender combined with knight and cleric, you shouldn't use footman because they're hit hard but very fragile and only good for a group of weak enemy such as goblin because they have AOE dmg, use knight and cleric instead they're the best tank and archers for Damage dealer

So back to archers, equip them with fire arrows and at least one of them spiky arrows, why? because the enemy will try to escape and your archers will waste their time chasing them, with spiky arrows they can't escape so your archers won't waste time chasing them

Spam a lot of archers because the best defense is a good offense, those ogre and orc knight will die very very fast, also pick their healer first, with a group of archers, you can 1-2 shot their cleric
Let the bodies hit the floor!

Archer in A20 is kinda clunky, they won't move themselves to the spot where they can shoot the enemy, you must order them to attack manually
I think it's because the new sight registration that also applied to turret, in previous alpha, your turret & archer can shoot through a bit blocked place, like weird shaped window, a pole, etc, but now they must have clear sight of the enemy

My team currently is :
2 Knight, 2 Cleric, 4 Archer, 3 Engineer
(I switch my herbalist to cleric when he's idle, and switch him back to herbalist whenever I need potion, I also switch my blacksmith to engineer when she's idle, and switch her back to blacksmith when I need blacksmith)

Archer Placement

It's annoying when you place your archer on top of the walls and suddenly they decided to climb down and take the enemy at close range, usually it's because the archer's attack pattern which they shoot then they'll run back a bit and they just lost enemy sight.

The best placement for archers :
1. Make a room with a lot tall window & ironclad door to prevent your archer abandon their post
2. Archers can shoot through tall window and somehow the enemy archers kinda ignore your archers if you put them behind windows
3. You should place knight near them or just put 1 knight into your archers group

AI enemy always prioritize knight over everything, also keep in mind that enemy archer do have longer range than your archer even if you place them on top of the wall, so placing your archer at open place is no no

You should manually order your archer to attack enemy archer, because AI always prioritize on knight / tank

Enemy archer is resistant to arrow & trap damage, while their warrior, knight and ogre very vulnerable against it

You can put chest filled with food & bed so they guard their post all day long

Engineer
Engineer can craft traps and turrets, at level 6 they can place 8 turrets & 12 traps!, how wonderful!
Engineer very slow to level up,repairing turrets, traps, door is the fastest way to level up, you must tick off haul & mine so they won't help carrying item and focus on repairing stuff

Also if you have more than 1 Engineer, you can have more turrets and traps placed

To level up low level engineer, just tick off job for high level one, so the low level engineer do all the repairing, crafting, etc. or just change job the higher level one.

Turrets can shoot through the door so do archers



Traps
Traps deal a ton of amazing damage, and very good to kill enemy tank instantly, the trade off, is trap only 1 use and need to be repaired to be use again, Enemy archers will shoot and destroy traps whenever they can so put them at bottleneck place and covered place

Use your knight and cleric team to lure enemy tank to traps.

Traps can be placed behind 1 block thick wall, and it still can hurt enemy through wall, but beware, sometimes they can destroy your trap through wall


Turrets
Turrets deal nice dps overtime, but they're fragile and enemy archers can destroy it, a group of archers can 1-2 shot it, so beware don't just put it everywhere. when it destroyed you will lose some of the materials, and it's quite expensive, so put them at bottleneck & covered place

Since A20, turret behavior has been changed, your turret must have clear sight of the enemy in order to attack, the picture below will explain

Door Placement
Tired of Ogres destroyed your precious door or getting annoyed because you must split half defense force to eliminate the Ogre?
Fear not, because with this design, ogre will never touch your door ever again and your hearthlings still can use it to get in and out
To build this design you must :
- Place your door farther behind your open entrance, AI automatically will seek open entrance but Ogre will seek door first then the open entrance, so you must place your door behind your open entrance
- If Ogre chased your hearthlings to the door, they will try to break it, this mean Ogre will seek nearest door



Bottleneck Entrance
Make entrance full of traps and turrets so the enemy can just walk in and die fast and efficient instead of closed base with a lot door, I know the enemy won't attack you if your base isn't accessible but there is an ogre who can destroy door, and sometime when there is nobody near them, the warning won't pop out, and when your base breached, other enemy will flood in like explosive diarrhea

Make so the turrets and traps covered from enemy archers

Lure their tank to your traps so they die instantly

Moat
Make moat outside your entrance and put some ladder, so the enemy will using that moat to enter your base, this way those pesky archers can't shoot your traps & turrets and they didn't programmed to flee by climbing ladder, so when they climb up ladder, they will realize at this time, they already f**cked up

Moat can also be used to close combat your enemy tank so their archers have limited sight
Moat can also be used as wall

Cheap Design :
Drop Dead Faucet
This design proven quite efficient and it's simple to build and can be modified in many way
+ Archer can't target your turrets & traps
+ You can choose where enemy should enter
+ With careful planning this design can fend off invaders automatically (no micro-ing)
+ You can put labirynth and put many traps there or put the traps at ladder
+ Cheap & efficient

- Getting loot quite annoying

The design in the video is basic (I plan to made 4 way drop dead faucet later), you need to add wall 3 block high + ladder and put turrets on top of that so enemy archers can't flee (remember AI didn't designed to flee via ladder except they still on the ladder

The 4 way drop dead faucet proven good to gather enemy from every corner but also very good to scare the hell out of my town heartlings, oh what a flying horror!


Bad Design :
Maze or Labyrinth (it's labyrinth, sorry my bad)
Ever thought a tower defense labyrinth will work out in stone hearth?
It won't because :
- Enemy archer can get clear sight on your knight / turret easily
- It's not that long, your turret only can land 2-3 hits before the enemy reach the end of the maze
- If the enemy reach the end of the maze, your turret efficiency crippled
- Too many micromanagements
- It's just not efficient

Thanks and enjoy