Good storylines to accompany adding another player to the game?

Question

I just ran my first two sessions as GM and we are probably going to be adding a 4th player to the group soon (making 5 of us total). I'm trying to thing of a good premise for the party to meet the new character and be joined by them and not just have the new character appear into their midst all of a sudden as if they were there the whole time. I'm going to let the new player make their back-story and then try to find a good way for them to get mixed in to the adventure. The stereotypical situation where the party finds the new player being attacked by goblins and the new player pledges to join them after being rescued would work, but I'm looking for something a bit more than that.

Are there any good guidelines/examples for adding a new player to the party story-wise? How can I make the meeting of the new character and the party a momentous occasion instead of just a "Hey, wanna join us?" situation? What good twists can the addition of the new character provide to help in this respect?

---

NOTE: Examples are wonderful and highly welcome, but please also mention the process of creating the storyline so this is more than just an "accumulate a list" question. :D

Related: What are some good stories for how the players came to start adventuring together?

Answer 1

Here are the steps I would take:

1. Make sure you understand the group's current goals.
2. Get together with just the new player and work together to design a character that has at least one common interest with the other characters.
3. Still with the new player, design a scene where the new player meets the party.
4. On your own, design a scenario where the new player contributes to the party.

Now here's an example of all this in practice:

1. The party is a tightly-knit bunch of brawlers and swordsmen, all from the same town, trying to track down the evil wizard who burned their hometown to the ground. Currently they've found out where one of his evil wizard buddies is at, causing some sort of ruckus in a village in the woods.
2. You get together with the new player and explain what the party's up to. Together, you come up with a character: a young wizard who was orphaned (by the evil wizard, though the character doesn't know that), then taken in and taught the art of magic by a kindly old man (the same wizard, of course), but then fled when he realized that the old man was actually a bad guy. This new character doesn't have a goal yet, but he has a common interest with the party -- stopping the evil wizard.
3. Now it's game night, and the party is in the woods near the village where the evil wizard's evil buddy is hanging out. While they're busy checking out the village from afar before going in, they find someone else in the woods doing the same thing -- a mighty paladin, eight feet tall, a grand defender of peace and justice, come to defeat the wizard. But the illusion falls flat, and soon enough the party sees through it. It's just a teenage kid, but one who's amazingly good with magic for being so young. Introductions all round, turns out everyone's there to see what evil deeds are afoot.
4. The party's in town, and they make an attempt to get into the bad guy's hideout. Having a wizard in tow turns out to be pretty helpful, as he can recognize all kinds of dangerous things that a bunch of fighters might never know about.

After just one session, the new character has both found some good allies and proven his worth to them. If the new player decides to stay in the game after that night, it'll be very easy for their character to be a regular part of the group.

Answer 2

Another idea that works well is to have the current party recruit the new PC. Maybe they need a medic or warrior or whatnot which just happens to be the new player's character. A good way to build this in is to have the new character linked to either one the existing characters ("you remember that you used to know a guy from school who joined the Legion and you heard from your sister that he is back in town") or have the new character be part of the plot already ("you mean, you are fighting against CASE NIGHTMARE GREEN? Sure, I'll help!").