Base Design Principles: Compartments, Funnels, Traps

Design from the attack backwards

A base is not a picture, it is a set of guesses about how someone will come at you. Every good layout starts from the same question: what is the strongest attack I will face this week, and where does it want to walk?

That is why the useful principles below are all about paths. Buildings do not defend. Buildings plus the paths between them defend.

If you want the current answer for the top levels, read defending Root Riders and RC walks alongside this page. What follows applies at every Town Hall.

Compartments

A compartment is any space fully enclosed by walls. Its purpose is to cost the attacker something: a wall break, a spell, or ten seconds of troops standing still.

Rules that survive every meta:

• Every compartment does one job. Stall the army, split it, shield one key defence, or bait a spell. If a compartment does none of those, it is decoration and it is giving away free pathing.
• Small beats large. One fat core is the single most punished shape in the game right now. It is exactly what a Meteor Golem split or a Super Yeti smash is paid to hit.
• Uneven on purpose. Compartments of different sizes force troops to keep retargeting and pull them off their healers. Even, regular spacing gives a Hog or Root Rider pack a clean loop.
• Nothing valuable one break from the outside. If your Town Hall or your Monolith is behind a single wall on the widest face, that face is where the attack lands.

Wall pieces are finite, so compartment count is a budget. You have 250 wall pieces at Town Hall 9, 275 at Town Hall 10, 300 at Town Hall 11 and 12, and 325 from Town Hall 13 upward, and that ceiling has not moved since. Every extra internal wall you draw is one you did not use somewhere else.

Funnels: you build one or the attacker does

An attacker’s first thirty seconds are spent building a funnel, which is a cleared lane that stops their main army wandering around the outside. Everything they do before the core is about that.

Your job is to make the natural funnel end somewhere useless.

• Do not leave a soft corner. Queen charges and Royal Champion walks start where the outer buildings are weakest, every single time.
• Keep the easiest lane pointed away from your Town Hall, not at it.
• Make the two easiest sides different from each other, so the attacker has to pick one and commit rather than getting the same result either way.
• Force wide turns. A pack that has to swing around an off centre compartment loses tempo, and tempo is what a timed attack runs out of.

Trap zones, not scattered traps

Traps spread evenly across a base do nothing. Traps concentrated where you have funnelled the attacker do a lot.

Pick one story per base and commit to it: anti hero walk, anti smash, or anti cleanup. Then place accordingly.

• Giant Bombs in pairs, in the gaps between defences that sit two or three tiles apart. That is where a Hog or Root Rider pack lands. You have 8 Giant Bombs from Town Hall 17.
• Seeking Air Mines behind the Air Defenses, on the side the air army will come from, not next to the Town Hall. There are 9 from Town Hall 17.
• Skeleton Traps in the corridors, where the defenders spawn into a pack rather than beside it. You get a fourth from Town Hall 14.
• The single Tornado Trap you unlock at Town Hall 11 belongs on the choke point where troops have to bunch up, not in open ground.
• The Giga Bomb, one per base from Town Hall 17, wants the compartment an attacker commits their tanks into.

The one common failure: traps against the wall line. The wall line is where the attacker expects trouble.

Air Sweeper angles

You unlock your first Air Sweeper at Town Hall 6 and your second at Town Hall 9, and that is all you ever get. Two buildings, two decisions.

Point them at the two widest open faces of your base. Not at corners, not at each other, not at the side that happens to look untidy. Air armies line up on the flat, open side because that is where they can spread, and a sweeper aimed there breaks the formation before it reaches your Air Defenses.

Speaking of which: you have 4 Air Defenses from Town Hall 9 and never more. Spread them so no two share a compartment and none sits on the outer ring. Two Air Defenses in one compartment die to one chain of Electro Dragon damage, or to one set of Lightning Spells.

Never stack the high value defences

The most expensive mistake in modern base building is putting your best defences in one place. A Siege Blimp, a Freeze plus hero drop, or a single Giant Arrow down a straight line is paid for entirely by what it can reach in one action.

Two structural facts change the middle of your base at the top levels. From Town Hall 17 the Eagle Artillery no longer exists as a separate building, because the Town Hall and the Eagle merge into the Inferno Artillery. At Town Hall 18 the Town Hall stops being a defensive building altogether and a Guardian patrols instead, with only one of the three active at a time. Both changes mean the centre of a modern base is worth less on its own than it used to be, and the compartments around it are worth more.

Practical placement notes that follow from that:

• Keep the Super Wizard Towers and the Revenge Tower in different compartments from the Monolith.
• Put the Revenge Tower somewhere hard to reach early and hard to snipe from outside, since it only becomes dangerous once a chunk of your base is gone.
• Leave the geometric centre slightly plain. An automatic drop lands there, and it should be worth less than it looks.
• Give your key defences depth. Anything a Thrower can reach over the outer wall from outside is free value.

Depth and the outer ring

Your outer ring is a resource. Collectors, camps and other low value buildings belong there, doing three jobs: absorbing cheap troops, blocking a clean approach, and stopping anything being stranded outside where Archers farm it for nothing.

Do not park working defences on the perimeter unless the base needs coverage there. A defence at the edge dies in the funnel phase and never fires at the real army.

A short checklist

Run any layout, yours or a copied one, through this:

• Is the Town Hall more than one wall break from the widest face?
• Does every compartment have a job?
• Are the four Air Defenses in four different compartments?
• Are both Air Sweepers pointed at real entry sides?
• Are the highest value defences in different compartments from each other?
• Are the Giant Bombs in the gaps troops actually land in?
• Is the Clan Castle unlurable from the edge?
• Would a mirrored attack on the other side get the same result? If yes, the base is too symmetric.

You can test all of this without spending a builder: start from a layout that already applies these rules on a hub such as /th17/ or /th18/. Every layout page shows the full base picture, so you can rebuild one in a spare slot and try it. See anti 3 star vs anti 2 star to decide which target you are designing against.