Shield is a status effect in Into the Breach. A shield will absorb any non-fatal damage once, and prevent status effects while it is active.
Description
Shields can be applied on Mechs, Veks, structures, other allied/enemy units, and mountains. A shield can be applied on the Supply Train, but it's considered one shield even though train has two units; attacking on any part of the train removes shield from whole train and conversely, applying shield on any part of the train grants shield on the whole train.
The shield persists through turns indefinitely, only disappearing once damage removes it. Any status effects such as Fire and A.C.I.D that the tile has applied will immediately affect the unit after the shield is removed.
A shield sacrifices itself and completely blocks any single attack from the following sources, regardless of the damage amount:
- Vek attack (including Psion Tyrant
damage) - Friendly weapons
- Blocking emerging Vek spawns
- Collisions
- Explosive Decay
damage
Intuitively, when combo damage (e.g. damage + push collision) happens in one move, the first damage breaks the shield and the second damage will land on the unit. It's important to note that AOE damage like Electric Whip will hit units with two segments (such as the train) twice, thus will still damage a shielded train.
Shields also block the following status effects without sacrificing itself:
Note that applying a shield on units already inflicted with those status effects doesn't remove them, and won't prevent Fire damage. Ending the turn on a tile with Freeze Mine will remove the mine without sacrificing the Shield or freezing the shielded unit. Casting a shield onto a frozen unit will make it both frozen and shielded, which is resistant to two attacks.
A shield can not block any 
Instant Kill attacks, including:
- Self-Destruct
- Satellite Rocket launches or being rammed by the Supply Train
- Falling in a Chasm Tile
- The Mosquito Leader's attack
- Environmental kill effects such as Air Bombing or Lightning Strikes
Abilities and Weapons That Grant Shields
- Missions with only 1 objective will start some buildings with shields.
- The Auto-Shields passive module, which makes a building get a shield after it has been attacked once.
- The Shield Projector Weapon and similar; e.g. Defense Mech in the Zenith Guard Mech Squad.
- Certain upgraded weapons, such as the Spartan Shield and Grappling Hook
- Shield Tank, a purchasable classless deployable weapon.
- Some Cannon-Bot enemies, the Bot Leader boss, and some stationary units from bonus objectives in Pinnacle Robotics.
- Bethany Jones' skill.
- Mafan's skill.
- Adam's skill.