Planetary Debris

Planetary Debris is an operation mechanic in Arknights, introduced in Lone Trail.

Overview

Representing space debris in the orbit of Terra, Planetary Debris are treated as an enemy unit that blocks the path of enemies and prevents friendly units from being deployed on its position. The Debris can only be attacked by friendly units adjacent to it and takes no damage at all when attacked; should the Debris is attacked 20 times or shifted with a force of at least 2 while stationary, it will drift (move) towards the direction the attack came from at the speed of 4 tiles per second, dealing 3000 Physical damage upon colliding with units in its path; enemies take 2.1× damage (3.2× in CW-P-1 and CW-P-2) and be pushed back with a force of 1 while friendly units take 0.4× damage in CW-P-1 and CW-P-2. Changing the gravity will also forcefully move the Debris towards the gravity's direction.

Keep in mind that the Debris can only be moved through "rails" represented as tiles with yellow holographic stripes.

Star Ring

Kristen can turn Planetary Debris into Star Rings which have the following properties:

• 12000 HP (15000 in CW-EX-8 and CW-S-4), 100 ATK (used to scale the damage it deals as explained below), 3300 DEF (3550 in CW-EX-8 and CW-S-4), 60 RES (70 in CW-EX-8 and CW-S-4), and an aggression level of 1.
  • When Kristen is on her second phase, all Star Rings have their HP increased by 50%.
• Unaffected by gravity.
• Loses 50 DEF and 1 RES when taking damage.
• Deals Arts damage equal to the Ring's ATK (120% ATK in CW-EX-8 and CW-S-4) every second to friendly units in the surrounding tiles and reduces their ASPD by 25.
  • The damage is increased to 120% (140% in CW-EX-8 and CW-S-4) ATK once Kristen is in her second phase.
• When Kristen activates Heat Death, when destroyed in her second phase, and when Kristen is defeated (unless if she is being Silenced at the moment), explodes after a delay of 2 seconds, dealing Arts damage equal to 7× (9× in CW-EX-8 and CW-S-4) the Ring's ATK to all friendly units on the map.
  • In the latter two cases, all enemies present at the time will also have their speed permanently increased by 10%, which can stack without a limit.
• Reverts into a Planetary Debris when destroyed.

Command Panel upgrades

Command	Information
Overweight α	Increases collision damage against enemies by 90% Collision now Stuns enemies for 1.5 seconds
Overweight β	Overrides Overweight α Increases collision damage against enemies by 140% Collision now Stuns enemies for 3 seconds
Gravity Awareness α	Increases collision shift force by 1 Reduces collision damage against friendly units by 30%
Gravity Awareness β	Overrides Gravity Awareness α Increases collision shift force by 2 Reduces collision damage against friendly units by 60%
Weightless α	Reduces the number of hits to move the Debris to 15
Weightless β	Overrides Weightless α Reduces the number of hits to move the Debris to 10
Initial Velocity α	Reduces the force needed to instantly move the Debris by 1 Extends the Debris' drift duration by 1 second
Initial Velocity β	Overrides Initial Velocity α Reduces the force needed to instantly move the Debris by 2 Extends the Debris' drift duration by 2.5 seconds

Interactions

Enemy	Interaction
	Repulses Planetary Debris that are adjacent to them.
	Kristen takes 70% less damage from Planetary Debris' collision in her first phase. Turns the closest Planetary Debris into a Star Ring on the first phase (30 seconds cooldown; 10 seconds after spawning). Turns all Planetary Debris into Star Rings upon entering the second phase.

Appearances

Planetary Debris are featured in all CW operations except CW-1, CW-2, and CW-6.

• In CW-TR-1 to CW-5, the Planetary Debris is named Rock and only serves as an indicator of where the gravity is currently pointing at.
• In CW-P-1 and CW-P-2, the Planetary Debris can be controlled by tapping on the rails.

Trivia

• In CW-EX-8, the two Planetary Debris on the right side of the map will despawn after 999 seconds have passed.
  • When this happens, the "leak" sound as if an enemy had entered a Protection Objective will be played without causing Life Point losses.
  • Both Debris are included to the enemy counter (though excluded from the maximum count), causing the enemy count to went past the maximum cap of 59 if only Kristen who remains at this point.