Deals
A deal trades systems and credits directly with another player, worked out inside a conversation and settled once every system in it finishes its trip.
Proposing a deal
Open a conversation with the player you want to trade with and hit Propose.
Each side can put in up to three systems and any amount of credits. A basket can be systems only, credits only, or a mix, on either side.
Credits you offer are taken out of your treasury the moment you propose, and held until the deal settles or falls through. You get them back if it's declined, withdrawn, or expires unanswered.
Offering a system doesn't lock it up. It's still fully yours to build on or move fleets from, and you can put it into more than one open deal, right up until someone actually accepts.
Left unanswered, a deal expires after three days, and any held credits return to you.
Accepting a deal
Any credits the deal asks of you come out of your treasury the moment you accept, and are held the same way the proposer's are. If you can't cover them, the accept is refused and the deal stays on the thread.
Accepting doesn't move anything instantly. Every system changing hands sends a claim flying from one of the receiving empire's own stars to the system it's acquiring, the same way a fleet crosses the map, so distance matters: a trade with a neighbour lands quickly, one across the galaxy takes a lot longer.
When a deal moves more than one system, they all move together. It settles the moment the slowest claim lands, and every system in it changes hands at that same instant. Nothing transfers before then.
A fleet does not come with the deed. Any fleet parked at a system you trade away flies to your nearest other system in range, and a fleet that was out on a mission does the same when it comes home to find the star traded. Either way it's lost only if nothing of yours is close enough. A traded star otherwise arrives as it actually stands, so one a rival's NPCs had been sieging doesn't reset its loyalty the way a captured star does.
What can stop a deal
A deal can be refused before it's ever accepted, or fall through afterward, once its claims are already in the air:
Neither side can be traded down to nothing. A deal that would leave either player with no systems at all is refused.
A system already committed to another accepted deal can't be promised twice. Offering the same system in several open deals is fine. The first one accepted goes through, and the rest are closed out at that moment, with any credits they were holding returned.
Ownership has to still match what was agreed. If a system in the deal changed hands before it was accepted, or before its claim landed, the deal falls through.
An incoming attack does not block a trade. You can trade away a system that's currently under attack, and whoever holds it when the attack lands takes the hit.
A deal with systems in the air either completes in full or not at all: if the galaxy has moved under it by the time the claims land, nothing changes hands and any held credits go back to whoever put them up.
Daily limit
Every empire can only trade away so many systems in a rolling day: 5% of what you currently hold, rounded down, with a floor of 3, so even a small empire can complete a two-for-two trade. It counts from the moment a deal is accepted, not from when the systems land, and it's checked separately for each side, so a swap counts against both of you. Only the systems leaving your empire count. What you take in is free.
Never let your sense of morals prevent you from doing what is right.
