Hello,
After looking through the region known as n_northtaigaplot1. I feel confident in saying that TNT can be denied for this warclaim.
Ladders will be allowed,
As well through RP a GM can place one block of tnt and ignite it to simulate going through gates and doors ((Rp'd as a hand ram)) ((Doors and gates only))
Larger siege equipment such a trebuchets and onagers would be limited to going this island http://i.imgur.com/jCIc60B.png, ((Rply the seige equipment would be disassembled and brought over the small bridge and reassembled.)) As well the trebuchet could only be fired once every 5-10 Minutes ((Due to the fact only one shot at a time could be brought by hand over the small bridge)).
I will also inspect the area again closer to the date of war to ensure no defenses were placed after my original inspection.
Tdlr
No TNT
Large seige equipment may only shoot once every 5-10min
A GM may place one tnt and ignite it to get through doors/gates ((Not walls)) With proper roleplay.
Lift signs should not be destroyed during the battle
Ladders
Use of siege equipment
Now you just need a time it appears! Good luck to both sides.