A castle gate is a pair of thick, wooden doors constructed (by one or more workers) at an entrance of a castle to provide a defensive barrier that hinders the infiltration of any threats. Like other construction instruments, the doors are destructible and are repairable by workers. Depending on the geographical location of or the map in which castle resides, it may be protected by multiple gates or none (as in the case of Sugar Cove and the soccer field).
The doors mechanically yield only to their corresponding team's players. In other words, a Blue castle's gates will not open for a Red player. It is also not possible to bypass the gate regardless if the doors are swung aside, as there is a pair of dotted grids (one grid per door) which denotes invisible barriers that prevent the further passage of a hostile or neutral entity.
The destruction of merely a single door is necessary to access the castle, as the invisible barriers are present only when the door is fabricated. The gate's health is the highest of any construction instrument (surpassing those of the ladder and the springboard). The axe of a worker deals the most damage to them, though there are other effective means of demolition, such as the bomb of a pirate's ship.
It is nonetheless possible for enemies to bypass an erected gate. However, only two methods exist: becoming intangible as a ninja or jumping (i.e., as a reaper). Of course, it is also possible to enter a castle without any interaction whatsoever with the doors: using ladders, springboards, cakes, catapults, and locomotive outposts.
A door costs 3 units of lumber. It is typical for a team to possess 6 units of lumber at the commencement of a battle, though whether or not that is true for a specific battle depends on the map.