The guild allows for the recruitment of tunnelers, a cheap siege unit.
Tunnelers operate by digging holes outside a castle (known as the tunnel entrance). Then, he starts digging towards the nearest wall segment (not tower). When they reach the end, the tunnel collapses, dealing huge structure damage in a small area. The tunneler is also lost in the process.
Tunnelers cannot dig under moats. Their tunnels can be collapsed, however, by enemy units choosing to attack the entrance of the tunnel. If the entrance of the tunnel is destroyed, then the tunnel will collapse and the tunneler will be lost.
Tunnelers are used solely for creating breaches or destroying buildings in enemy castles. Other weaponry can be cheaper and more powerful - however, they are quite accurate and if they are provided (they occasionally are) it makes sense to use them. They can also be used as melee troops, although they are by no means ideal for this purpose.
- Curiously, tunnelers speak with very strong Welsh accent, possibly due to the mining connection.