You don't play, you coach. Write your diplomat's standing orders, watch 50 matches, read a replay, change a line. Three tries at today's world; your best stands.
Each match puts your diplomat (Halden) against five rival nations drawn from a pool of ten. You can't see their orders; the replay shows what they did.
Checked top to bottom. In each phase, the first rule that applies decides; every offer rule that applies makes an offer.
When no rule applies, your diplomat offers a 1-for-1 trade of its most plentiful resource for what it has least of, accepts fair trades that help it and pacts from anyone who hasn't raided it, and holds.