What determines what races a slaver can provide?

When encountering a slaver ship, you have a couple of options to acquire a new crew member. You can buy slaves, fight to receive a slave as a bribe, or kill the slaver crew to gain your choice of slaves.

Is there anything that affects which races are involved, or is it completely random?

For example: If I am in an Engi controlled sector, am I more likely to get an Engi from slavers?

Solution 1:

There are a couple different ways to resolve a slaver encounter which will result in new crew members:

Friendly Slaver

• Buy a slave.
  • Receive 1 random crew member.
• Using a level 2+ Teleporter.
  • Outcomes 1: Receive 1 random crew member and fight the slavers.
  • Outcomes 2: Receive 1 random crew member and fight the slavers.
  • Outcomes 3: No crew member up front, but fight the slavers.
• Fight the slaver scum.
  • See below.

Pirate Slaver

• Fight the slaver scum.
  • See below.
• If you have level 6+ Engines, you can attempt to outrun the slavers. If this fails, you will fight the salvers.

Fighting the slavers:

The outcome of the fight can lead to a new crew member even if you got one through the teleporter dialogue option.

• Slavers surrender.
  • Receive 1 random crew member.
• Kill the slaver crew.
  • Outcome 1: Receive 1 random crew member.
  • Outcome 2: Receive your choice of a Rock, Mantis, or Engi crew member.
  • Outcome 3: No crew member.
• Destroy the ship.
  • No crew members.

All in all, crew members you receive are of a random race, but there is an option to get your choice of Rock, Mantis, or Engi if you do things correctly.

Solution 2:

In my (limited) experience, if you kill the crew of the slaver you get your pick of the slaves, which is one of each main race (Engi, Human, Rock, Mantis). That suggests to me that the common races are always present, and if you do one of the other possible approaches (teleport, accept surrender) then you get a slave randomly selected from that pool.