>Supply
Every five turns, you gain some number of supplies depending on your trade and buildings.
Supplies can be used too...
-Finish building production
-Recruiting soldiers faster
-Trade
-Sending soldiers to some other region. (The supplies needed is different by the distance and how many soldiers your sending.)



>Trade
Trading gives supplies to both players and make a physical connection.
Requirements
-Both players must have an open trade route through a market or docks.
-Trade route must be established through actions

>War
1 Soldier [C : E, D: E, M: E]
C = Combat
D = Defense
M = Movement
E = Rank E, (Ranks can go to D, C, B, A, S, SS, SSS]

Generally, it'll cost 50 supplies to send 1 soldier to a neighboring nation. (WAR IS EXPENSIVE)
There will be a strategy roll between the attacking and defending, but it mostly comes down to stats.