40d:Liaison

Liaisons are emissaries from different civilizations that accompany traders to your fortress. They can have different names (Humans will send a guild representative, dwarves will send an outpost liaison), but their functions are the same. Like actual diplomats they are listed as diplomat in the unit list. Dwarven liaisons will speak with your leader, one of:

• Duke/Duchess
• count(ess)
• baron(ess)^[Verify]
• mayor^[Verify]
• expedition leader

Human liaisons will only speak with your broker. Their function is to ask which goods you would like to have sent with their next caravan (for a higher price), and inform you what goods they would like to buy from you the next time, which they too will pay extra to purchase.

If your leader is dead, then you must assign a new one using the n screen before the liaison arrives or he/she will leave without a meeting.
If your liaison is dead then you will never get a replacement so protect him well if you rely on the caravan for a source of something that you request.

Make sure to turn off all labor for the dwarf who needs to meet with the liaison, even the "dwarves all harvest" order, because your leader tends to walk away from the meeting, and liaisons will eventually get depressed or go berserk if they do not get their meeting. This also causes a message saying "A trader went away unhappy" although it's unknown if this has any current in-game effect. A liaison can also go insane if prevented from leaving; this can happen after as little as two months of game time.

If you are desperate to complete a meeting, consider locking the door on the meeting room until the meeting is complete. You don't even have to catch both in the office, the liaison is so keen on his bureaucracy, he will happily shout through the door, or even a thin wall (mine coincidentally picked a wall that had an engraving of one of the Dwarven leaders. Psychology, anyone?). A sleeping dwarf leader can be woken up by deconstructing his bed, although this will often generate an unhappy thought. Lastly, an easy way to force the leader into the meeting room is to draft him (this can cause an unhappy thought if he has no war skills) and stationing him in the meeting room. Undrafting him may or may not be necessary to force the meeting to start.

The meeting can take place before, after and even "during", that is, between, trading sessions.

The meeting usually consists of 8 screens with breaks, the breaks giving your leader a welcome opportunity to walk away from the meeting. Don't think you are done until the liaison confirms it and says farewell!

The entry point on the map for a liaison is determined before that of the caravan wagons. This can result in the liaison taking a different route to your fortress than the rest of the caravan if the route chosen is not suitable for wagons; the wagons will then enter from a different spot. This means the diplomat has to travel unprotected but this is really the only downside to forcing the wagons to use one particular route. The liaison will then also leave without the caravan once the meeting is done.

Conducting a meeting in a public place can generate an unhappy thought. Conducting a meeting in the leader's private office can generate a happy thought based on the quality of the room^{v0.27.176.38c}.

Oddly enough, liaisons don't need to eat, drink or sleep. There is a statement from one of our mayors on this:

Ironblood: "This damn human thingy keeps following me around, suckling on me when I pause for too long. I think it's a foreign custom, but I dare not emulate. He's all disgusting and clean. Though his clothes are almost completely rotted off..."

Differences by race

The liaisons and diplomats sent by different races differ in certain ways.

Dwarven

The name of your dwarven liaison will be upgraded to names such as city or metropolis liaison, corresponding to your fortress development.
The liaison will stop coming if you have a King. This liaison comes from the Mountainhome, and if you have a King, then you are already living in the Mountainhome.

Human

The human guild representative will have different names based on the importance of your fortress. Such names include merchant baron and merchant princess.

Humans will also often send a diplomat separate from the guild representative when your fortress becomes important enough to rate a baron or better noble. This individual will only speak to your baron (or better), and generally says something inane such as "What a nice place you've carved out for yourself here." As the noble the diplomat wants to speak with never does anything anyway, you need do nothing to ensure the meeting occurs. If you're in a state of war with the human civilization, the diplomat may come proposing a peace treaty.

Elven

The elves will not send trade emissaries, but will occasionally send a diplomat who meets with your head noble (such as the Duke/Duchess) to talk about the "tree situation" at your fort. If you don't cut any trees he will actually be happy with you (a happy hippie - impossible). He may also appear and complain without negotiating an actual tree cutting limit (yet), but for most fortresses he will demand that you limit the number of trees you cut down before the elves return the next year. Once he complains about tree cutting, he will continue to do so every year afterward, even if you don't cut any down. Note that underground tower-caps also factor into the limit (who lets the sneacky elves peek in our caverns?).