Players can trade and make deals between themselves.  All deals are enforced by the Arbiter: the NPC who provides the world updates and the scrolls of power to challenge the legendary foes.

UNLIKE OTHER, SIMILAR 4X GAMES... You cannot voluntarily 'reneg' or 'break' a deal once made.  This means you cannot cheat each other out of resources/items/gold once you have struck an accord.  You can, however; decide you don't like the terms and simply choose not to participate at all.  This will be explained further down in the page.

You may negotiate with any other player via Private Message as you see fit, and discuss strategies, plans, gang-up on other Usurpers, etc.

You may also make trade deals:
Trade Deal: You may barter/trade with any Usurper to trade X resource/good/item/extra/Unit for any similar benefit.  These deals will be enforced by the Arbiter.  If two Usurpers promise X and Y to one another - X and Y will be automatically sent between them, arriving the following week.  Once the terms have been agreed: you cannot say, "oh yeah - never mind - I pull my stuff back."  It's too late.

You may also make deals to attack a target together.  You may negotiate terms of 'division of loot' up-front.  If the two players end-up attacking the same target during the same week, and decide to 'join forces' - then the deal on how the loot will be divided will be enforced by the Arbiter.