If you’re in the Chinese rimworld community, good chance that you’ll be no stranger to the Sap KillBox (闷棍阵). Sap as in hitting your enemies behind their back with a stick

This killbox effectively takes advantage of the remarkable property of the wood fire generator (also windmill) that not a lot of people know about. The wood fire generator acts as a visual barrier for pawns, similar to a wall, but with the unique ability to allow passage. This distinctive characteristic enables the generator to be utilized as a sideways wall. When an enemy pawn passes through a generator, it temporarily loses sight and the ability to aim. As a result, strategically placing animals or heavily armored melee pawns around or on top of the generator creates a situation where enemies can be melee attacked for free before they regain their vision and will be forced into melee combat afterwards. Additionally, due to the generator's inherent high wealth, enemy pawns often engage in melee combat with the generator itself rather than focusing on the player pawns beating the * out of them.

A creator on Bilibili harnessed this property and developed what is known as the sap killbox. To ensure its proper functioning, the sap killbox needs to be linked to the most valuable room in your base. The enemy requires a clear view of the "wealth" in order to be enticed and funneled through the opening with the generator.

To position your undrafted pawns or animals on the generator, you need to set up and assign zones. There should be two pawns snugly positioned in the same zone on the left side of the generator: one responsible for attacking enemies from behind, and the other for repairing the exposed generator. The zone on top of the generator is for smart animals that can help you absorb damage and dish out damage. The drafted pawn on the right side of the generator should be heavily armored since they will bear the brunt of enemy attacks if they manage to get past the generator. Like any killbox, this setup requires enemy collision to be triggered when they enter.

The issue with the original sap box lies in its kill efficiency. If you're playing in later game or on harder difficulties, your pawns will spend an extremely long time dealing with a single raid since you're heavily reliant on animals and melee. This is where the singularity point comes into play. Introducing the 69 killbox (or the 9 killbox), a combination of sap and singularity kb, named after its unique shape.

The 9 killbox takes advantage of the singularity point property by incorporating doors to enable peeking, thereby introducing five additional pawns into the equation. Due to the singularity point, these five pawns will not be targeted by enemy pawns or mechanoids unless there are unintended items of wealth (such as furniture or torches) in the room they occupy. If such items are present, they may draw enemy aggression and allow the enemies to gain vision on the five pawns. Otherwise, it is an exceptionally efficient and powerful killbox that remains effective even in late game.

Fights still taking too long? No worries, it gets better - introduce to you the Differential KillBox that adds even more pawns into the equation.

Differential KillBox by Metro Nine

Reference videos:
https://www.bilibili.com/video/BV1CR4y1w7By/?spm_id_from=333.788
https://www.bilibili.com/video/BV1gu411B7M1/?spm_id_from=333.337.search-card.all.click&vd_source=1946e6df7dc0c032762c422d187a1508
https://www.bilibili.com/video/BV1AU4y1d75E/?spm_id_from=333.788.recommend_more_video.-1&vd_source=1946e6df7dc0c032762c422d187a1508
https://www.bilibili.com/video/BV1nK4y1S7oj/?spm_id_from=333.788.recommend_more_video.1&vd_source=1946e6df7dc0c032762c422d187a1508