A PUG, or Pick-Up-Group, is a group of strangers banding together to run an instance. Most instances can't be handled with less than 5 people, and if your friends aren't on (or you don't have any friends), then you may just have to settle for a PUG.
The "Looking for Group" icon is a small green eye on your task bar between the Social and Main Menu buttons. Most PUGs are formed by players using this resource to find other players who want to run the same instance. Other PUGs are formed by players loitering at the entrance of an instance and begging to join anyone who passes by.
Can I say, for the record, that Dustfire is NOT and NEVER WILL BE available for running instances with groups of complete strangers? Dustfire, believe it or not, has friends -- friends who won't let her subject herself to the social equivalent of eating kitty litter.
And even though I know that the people who have been asking me EVERY TIME I LOG ON to instance with them will never ever ever read this, I just want to say: No. I don't want to instance with you. It would be horrible, you're just asking me because I'm a priest, and after finding out I can heal about as well as an Oily Blackmouth, you'd end up leaving me to die.
I think I'm going to start paying more attention to their names and "ignore" them if it's the same people every time. Because I'm not kidding -- I've been asked to instance 1-4 times (by complete strangers) every single time I've gotten on since my vacation. I keep saying "No thank you." Some of them even tried to argue with me about it -- like if they pressed me hard enough, I'd stop questing and run to their aid. I'm sorry, but I'm a full level lower than the rest of my group, and that's after all the questing I've done this weekend. I'm playing catch-up. So I have that on top of all the extremely rational, sanity-saving reasons to say no to random people.
Now, how do I know PUGs are bad?
Let me recount a few stories.
Story 1 (Dramatized)
Guildmate 1: Level 44 Shaman
Guildmate 2: Level 36 Paladin
PUG 1: Level 40? Rogue
PUG 2: Level 38? Warlock
Dustfire: Level 33 Priest
Guildmate 1: Wanna run Scarlet Monastery Cathedral?
Dustfire: You aren't a complete stranger, so yes. Thank you very much.
Guildmate 2: Terrific.
PUG 1: GONNA AGGRO EVERYTHING!
Dustfire: I died?
PUG 1: I lived. No one else did, but I'm a rogue and can't resurrect you.
Dustfire: I'm pretty low level for this. Should I leave?
Guildmate 2: No, it's cool. I'll heal.
PUG 1: [leaves]
PUG 2: Let's go!
Dustfire: I died again.
Guildmate 2: I'll res you.
PUG 2: [disconnected]
Dustfire: Oh dear.
Guildmate 1: [very smart tanking]
Guildmate 2: [very smart healing]
Dustfire: [vampiric touch + shadow damage = tiny healings] + [Shields for everyone!]
[We 3 Guildmates Finish Without Dying Again At All]
Guildmate 1: Good job, guys. Gonna hearth. [hearths]
Dustfire: Ok! ^_^ [elated]
[upon leaving the instance]
PUG 2: [who has been standing by the entrance, probably waiting for another group] Oh, hi. lol
Dustfire: /wave [almost dies] [hearths]
That was actually a pretty cool experience, because we took down the bosses with just us three. It demonstrates the power of decent teamwork (and NOT overaggroing!).
By the way, disconnecting yourself is a sneaky tactic sometimes used to get out of a group without having the stigma of just leaving. I know Nevari has done it before, when she was in a group that was turning out to be one of the worst mistakes of her gaming career. But more often, people disconnect when one member leaves because they think that a 4-man team can't possibly run an instance. Irony was, we did it with 3.
Story 2 (Dramatized)
Two of our level 70 guildmates joined three level 70 guys from another guild for a Steamvaults run. Our guys had been waiting for a group all evening and needed a few drops and some reputation.
This is copied verbatim from my guildmate's post.
Jerks: Which way to the Key fragment?
Guildmate 1: Worry about the key fragment later... lets get some stuff done... we gotta open unlock this door.
Jerks: Nah... we don't open any doors... just go into the water...
G1: We are doing the whole instance right?
G1: Ok good.
G1: /spit Jerk1
G1: /spit Jerk2
Guildmate 2 (in Vent): HAHAHAHAHAHA! You make me laugh so much... I think you should be a comedian! On the television! And completely rich! Lets get married!
Jerks: Oh... we were just here for the key quest.
G1: So... when I asked if we're doing the whole instance and replied yes... you were lying... lying to keep us in your group so you could get your key and then ditch. It was your intention all along, and it's downright rude!
Jerk3: Don't worry man... we'll get another two guys for DPS
I'd wanted to add a third, where I went into an instance with nothing but a PUG, but didn't have the guts for it. Yes, ladies and gentlemen, I'm a coward. I'm afraid of really bad Warcraft experiences. (Seriously, I kept thinking about it, thinking I should do it for the sake of the blog, and then I'd cringe and back down. Like when someone dares you to belly-flop into a pool and you just know it's going to sting like the dickens. . . . Except this would sting for about an hour.)