Kalran: Tales of the four nations/Wall

Walls
"It protects us and keeps the enemies out. What more do you want?"

All factions possess walls to shield critical structures from unarmed engineer and infiltrator units, and to increase their defense values against most weapons. They are constructed in a hub/segment manner, meaning a line of segments will be automatically built between two hubs. Walls are extremely cheap and thus mass-producible, so a commander should always shield structures such as HQ or tech buildings. Do note that very big vehicles such as Doberman can simply crush walls. While basic infantry and Infiltrators can climb up walls, though they are frail while doing so.

Gate
"It's either this, leaving a giant hole for the enemy, or locking our forces inside."

All factions also use Gates to accompany their walls. Gates will automatically open and close when the commander or ally forces are going through it, but Gates are slighty weaker when compared to a regular wall.