I just got Bespin Gambit and read about the companions. I know the Ughnaught Tinkerer gets to deploy the droid, but how to the other companions come into play? I can't seem to find it anyplace.

R5 comes into play after Rebel heroes purchased the item card (it's a level 2 item)

Cam droid comes into play as Murne's reward from her red side mission

So those can't be used in skirmish?

4 hours ago, Ken on Cape said:

So those can't be used in skirmish?

Correct, afaik you can't bring cam droid or R5 into skirmish

If you look closely:

cam droid's auto +dodge would be game-breaking in skirmish, which will literally change the entire meta for all 3 factions to include figures that can do ~: -dodge or indirect damage (blast/cleave...)

R5's even easier to explain: there's no supply cards in skirmish

Once purchased, R5 Astromech can be taken into missions - the rebels can trade items before arriving, so you can change which hero controls it. R5 is an equipment, so it is improbable that the equipment limit of every heroe is reached (3 equipment per mission), but they do not need to bring R5 if they don't want to.

Pit Droid (Jabba's Realm) is put into play by a supply card, so it isn't for skirmish either.

junk droids can be used in skirmish.

Yes