I tend to have "Circus Troupe" parties in my games, but that's partly because my setting is a bit kitchen-sinky and tends to have Mos Eisley Chalmun's Cantina-esque locations in many big cities and even in smaller port towns, even though my setting has a lot of multi-directional fantasy racism between the different species (more a la The Elder Scrolls).
This works on a species mix level because it allows my players to play the characters archetypes they want to play. I find the class mix a bit more challenging for some campaigns; I've ended up using A-Team esque first-adventure plots where the inciting incident requires the NPC benefactor hiring a "crew of specialists" to deal with the problem, and then the crew become like Fast & Furious-esque "Fam'ly".
I often take cues from Record of Lodoss War and from The Lord of the Rings: The Fellowship of the Ring, Book II; both fantasies put together a kitchen-sink party of multiple species and classes for their missions. Each do it a bit differently though.
Book II of 6 for The Lord of the Rings starts with Elrond of Rivendell gathering representatives from all the free peoples of Middle-earth, should they choose to come, to take council and figure out how to combat the growing shadow. Some of these representatives actually came of their own accord on different and quite local business, but all of the representatives' businesses ultimately are ruled by the gathering shadows from Mordor and while the council is also trying to figure out how to best combat these threats on a political and military level, the Fellowship is formed as a team of specialists representing Humans, Elves, Dwarves, and Halflings for multiple reasons – in some cases, they are companions by virtue of a shared road until arrival at Gondor. But they're also companions because it's politically useful to have a mixture of different peoples. Gímli and Gandalf could help them treat with Lord Balin and get them safe passage through Moria; Legolas, Aragorn, and Gandalf would similarly be respected enough by the Elves of Lothlórien to get them safer passage on the other side of the mountains unto the River. Aragorn and Boromir would help them with passage through Rohan and Gondor should they take the southern route around Isengard, and if the Fellowship passed into the White City, these great Lords of Men, as would Gandalf, would leverage support on the next steps further.
Gandalf is this character respected by everyone, but it's quite valuable to have backup characters to support the legitimacy of such a quest. Remember that when Gandalf took a Hobbit and 13 Dwarves on a journey 77 years earlier, they did not get as warm a welcome in various places that did not like Dwarves. And Gandalf is prone to having to change his attentions to other matters mid-mission, so having others who can treat with different nations' leaders is critical for this Fellowship to pass safely to their destinations. Finally, Hobbits –– these Halflings may not have been members of this mission should Frodo not have offered to take the Ring himself to Mordor. But more so than a diversity of allies from different places, this quest should be supported by the trust of close friends and family that would do anything to support Frodo. In addition, as Bilbo had shown 77 years prior, Halflings are remarkably resilient and resourceful, and especially good in matters of stealth.
The lesson to take from The Lord of the RIngs Book II, Chapter 2 – 'The Council of Elrond', is that we can balance a party without prior bonds (in the trait, flaw, bond system of 2014 PHB) hired/volunteered into an A-Team alongside multiple members of the same species WITH prior bonds of "fam'ly" and/or old friendships.
Record of Lodoss War takes a different tact in forming the Party. Well, first we should talk about which version of Lodoss Touseki we're talking about – the 3 core replays were games of B/X D&D published in Comtiq Magazine to teach Japanese readers how to play D&D. So we're really talking 3 different parties each gathered in different ways. -BUT- a further wrinkle is that after the replays were published, the DM wrote novel adaptations which change and complicate some of the stories, and these novels then were the basis for a 1990 anime OVA (mainly covering Adventure 1 but also including a condensed adaptation of adventures 2 & 3), a 1998 anime TV series (covering Adventures 2 & 3 in their entirety, though changing a few elements for their ending), and multiple manga adaptations of the various novels & anime, each bringing their own twists to the tales. There's also Legend of Lodoss, a prequel novel series that had its own loosely-related Replay trilogy and more-closely relate manga – The Lady of Pharis – and there are a ton of other novels, anime, manga, and roleplaying campaigns set in the same worldspace that eventually left D&D to build their own roleplay game system – Sword World RPG (with Rune Soldier Louie and Legend of Crystania as the most well-known of these other storylines). But for a BIT of brevity, I'm focusing on the Record of Lodoss War replays and their adaptations.
Replay 1, Novel 1 "The Grey Witch", the 1990 Lodoss anime OVA episode 1-8, and The Grey Witch manga all start us off in Zaxon Village, though how the party is formed differs from medium to medium. In the Replay, all six party members are residents of Zaxon and depart south out of a shared desire for adventure. There's no particular reason they're gathered. We've got the Lawful M Human Fighter Parn and Lawful M Human Cleric Etoh (of the Light God Pharis), as well as the Neutral M Human Magic-User Slayn, the Neutral M Human Thief Woodchuck, the Neutral F Elf Deedlit, and the Neutral M Dwarf Ghim (as this is B/X rules, Elf and Dwarf are both species and class; Deedlit has elven shamanic magic to summon various elementals and is also effective with her rapier; Ghim is Gímli clone aka axe-wielding stubborn dwarf, though he is also a woodworker/craftsman). They each have different backstories and strong personalities, so the DM arbitrarilyn decided they were all sharing a destination south.
In Novel 1, the anime OVA, and the manga, there's instead an inciting incident related to Parn killing a Goblin from a nearby forest (after saving a young woman from it), leading to the Goblins attacking Zaxon Village. In the novel and manga, Parn is a mercenary who recently returned home from fighting in some wars in the deserts to the west, he wields his father's armor and sword – his father was a disgraced member of the Holy Knights of Pharis whom Parn want's to prove was not a deserter. The anime has him just living in the town with his father's sword and armor on display in a sort of family shrine a la what you might see in any Japanese house with a deceased parent. He's a complete rookie in the anime, too, but he learns quickly. In all the adaptations, Etoh is a priest recently returned from the Monastery of Pharis after graduating; he now needs to go on a pilgrimage before choosing a parish of his own. He has returned to Zaxon village as he and Parn were childhood friends in that town. Slayn the Magic-User is a resident scholar in Zaxon that the people turn to for guidance, but he's really into his books and it takes his old friend Ghim the Dwarf convincing him to get out on the road for real. Ghim is on a personal quest for the Earth-Mother Goddess Marfa's priestesses; he was saved by them after a mining accident, but now the daughter of the high priestess has gone missing. He's on a mission to find the missing daughter, and seeks out Slayn for help in this quest. Ghim is from the dwarf clan that live in the mountains near the Marfa monastery of Tarba, about a day's travel north of Zaxon, as opposed to just a wanderer with no home as in the Replay. In the adaptations, Deedlit and Woodchuck are -NOT- from Zaxon. That said, Deedlit is visiting the forests near Zaxon when the goblin incident goes down, and observes Parn and Etoh's efforts, at least in the anime. Woodchuck is not involved in this goblin story at all in the adaptations. In the ensuing encounter, Slayn and Ghim observe Parn's tenacity and Slayn is inspired to go with Parn and Ghim – now a party of 4 as ambassadors to warn the capital about the gathering monsters.
What happens next differs between anime and all other versions. In the Replay, the party approaches a Trading Post to the south. In the Novel and Manga, they arrive in the kingdom of Alania's capital - Allan City. Here in the city, Parn becomes drinking friends with the elf Deedlit who is at the same tavern, and Woodchuck the thief recruits them for a job from the Thieves' Guild (but totally above board – not theft, but trying to eliminate other thieves encroaching on their territory). Woodchuck has just gotten out after 20 years of prison for a minor theft, and wants to get his life back together, and this opportunity is too good to pass up. Slayn and Ghim meanwhile head to the College of Sorcery in Allan; this is where Slayn studied to be a Magic-User, but he finds his old mentor there at the destroyed school – recently razed in an attack by fellow former student Wagnard, who now serves Emperor Beld of the Dark Island of Marmo. It seems Wagnard is also involved with the thieves of Woodchuck's quest, so the team all now have a common adventure target. In the ensuing quest, they discover a painting amongst the stolen artifacts, strangely depicting the very priestess girl that Ghim is looking for. And so they have more adventures from there on.
The anime, on the other hand, has Parn meet Deedlit in the forest after a training session gone-wrong with Ghim, and then the whole group is attacked by Dark Elves and Kobolds (more like Gnolls in modern D&D, tho). These monsters are driven off by Allanian Soldiers from the nearby Fortress Myce, who then arrest our party on suspicion as well. While in jail at Myce, they meet Woodchuck who has been rotting in a cell there for a while. But the captain of Myce frees them when he realises Etoh is a priest of the God of Light. The captain then takes an interest in Parn and tries to train the young Fighter (who has been repurposed as our audience insert/perspective character), but the whole fortress is then attacked by Dark Elves, Kobolds, and Goblins, led by the Black Knight Ashram, who serves Emperor Beld of Marmo (see above). The party are NOT Allanian soldiers, and the captain makes them leave (but not before Parn rescuses Woodchuck from burning alive in his cell in the ruins of the fortress). The party tries to bring word of this terror to the capital Allan, but the city gates are closed to all outsiders, and Allan tells them that they have taken a position of neutrality in the invasion of Lodoss Island by the Marmo forces. So the party sets off in search of others nations that may take a more proactive stance against the invading monster armies.
All in all, Replay 1's party gathering was a classic "don't sweat the small stuff" gathering of the circus troupe, and the DM even remarks in his notes that their diverse backgrounds and personalities will be useful for intra-party conflict down the road. The adaptations, on the other hand, show how such a diverse party can be formed in stages, with some characters sharing bonds even if very loose ones (Slayn lives in the same village as Parn and Etoh, but he only knows them as much as he knows any other villager), other characters with stronger bonds (Parn and Etoh are childhood friends; Slayn and Ghim share a friendship going back years), and other characters that have no connection to the group prior to the circumstances of adventure. The Novel and Manga pull Deedlit in with Parn's infatuation towards the elf, their chance encounter and choice to drink at a bar together, and then solidify it with them being recruited by Woodchuck who saw A-team potential of these three differing party members. The anime pulls Deedlit into the story over -her- seeming infatuation with the young wannabe-knight, and then solidify it via her people's age-old conflict with the Dark Elves. The anime brings Woodchuck in seemingly by chance, but gives Woodchuck a more definitive BOND to Parn after the young knight took interest in Wood's wisdom about knights and where to learn to fight, and Parn's rescue of Woodchuck during the ensuing firestorm. The novels and manga never quite make Woodchuck as invested in a friendship with the party as the anime does, keeping him more as an ally of convenience who sees the party as a path towards bettering his lot in life, that he could double-cross in an instant if he saw a better opportunity come around. This different changes a critical scene near the end of the first novel as depicted in Episode 8, and his differing backstory also allows him to deliver some really poignent lines in the anime and be all around quite more likeable of a character in the OVA.
Replay 2 is probably the most divergent from the Novels/Anime/Manga in their gathering; it has the party hired by a mysterious benefactor in a "you all meet in a tavern" scenario focused on the Free City of Raiden. Multiple characters from this party did NOT make it into the equivalent Novels 3 & 4, though they appeared in quite different roles in Novels 2 & 5 respectively (Novels 2 & 5 are the only ones that aren't based on a D&D campaign Replay). Novel 3 gathers the party once again at Zaxon Village, and the Chronicles of Heroic Knights anime follows the novel in this regard. There is no manga adaptation of this Replay, but the manga adaptation of Novel 2 (and Novel 2 itself) features one of the party members from the D&D campaign - Fourth the Thief from Raiden, who is instead a mercenary in Novel 2 (but actually a Thief using the mercenary role as a cover identity). The other missing member of the party is Shari, an NPC female cleric added to the party by the DM because this team otherwise lacked a healer. She serves as a representative of their benefactor as well. Shari shows up in the 5th novel, given that the early chapters of that book take place in the Free City of Raiden (Fourth also shows up in that part of the novel, as a reference to the Replay, and also to show what happened to him after the events of Novel 2/the "Blazing Devil" manga adaptation). The remaining party members -ARE- in the novel and anime: Orson, a Neutral M Human Fighter; Shiris, a Neutral F Human Fighter; Maar a Lawful M Halfling ("Grassrunner in later adaptations + Sword World RPG; a bit like what you would get if you mixed Gnomes, Halflings, and Kender in a blender); and Cecil a Lawful M Human Magic-User. I'd also note that Maar has a radically divergent personality in the adaptations. He's played by the same player as Etoh was in campaign 1, and the replay doesn't significantly distinguish their personalities. But the novels and manga and anime give us instead Maar the Bard, a Grassrunner who is also a Thief and generally pretty Chaotic Neutral (Neutral in this Lawful - Neutral - Chaotic distribution). Maar in the replay loves singing and dancing, so the Bard extrapolation makes sense, but his "CN Halfling Rogue" archetypal elements seen in other media develop a bit from over the course of the campaign of the other party members taking his constant cheerfulness and positive attitudes and enthusiasm as being annoying or disruptive, and the for the novel, the DM decided to layer this two-faced personality onto the character, who is only using the party to get his thiefy-ends. This is likely why Fourth the Thief was removed from the 3rd & 4th novels and transferred over to the 2nd – his Raiden thieves' guild character isn't needed if Maar can serve that purpose. Cecil the Magic-User was played by Parn's former player and is an obsessive fanboy of Parn's who acts more like a Lawful Stupid Paladin than a Magic-User. Orson and Shiris are fighters and mercenaries; in the Replay, Orson is a fighter who dreams of being a King, and sees the war-torn world as a way to advance quickly. Shiris just wants good fighting companions here.
The novel and anime do NOT include Maar in the inciting incident; the rest of the party (minus Shari & Fourth) are present at Zaxon. This incident has Orson and Shiris as co-mercenaries on a job for the Evil Duke Lester/Raster of Allan, who was installed in the country by Marmo after the previous war as thanks for not getting in the way. They're trying to reclaim taxes from Zaxon, which haven't been paid since Allan allied with the Marmo. They know the leader of this "Free Army" based in Zaxon is the wizard Slayn, and are also charged with bringing him to meet his "justice" in Allan. But they're stopped by the combined forces of Slayn, his new wife (name is a spoiler), Parn, Deedlit, as well as their new friend Cecil. Parn is now a legendary wandering "Free Knight" - basically a ronin, not bound to any crown but fighting for freedom for all of Lodoss after much has been conquered by the Marmo. Deedlit and Parn are an item and travel together. Slayn and his wife live in Zaxon, but when these four character met again in novel 2, the King of Flaim offered Slayn the position of Court-Sorcerer, if he would have it. He's still considering. Cecil is a devout follower of him and Parn in the fight for freedom in Allania, so his character is much the same. But the NPC heroes + Cecil beat back the other 2 PCs, Orson and Shiris, even after Orson goes berserk – he's actually a Barbarian / Berserker in the adaptations, and has no emotions save when he enters his Rage state, after which he is possessed by the spirit of Fury. He enters this state after seeing Shiris in danger, so there's a bit of a romantic entanglement there. So Orson's character is VERY different between replay and adaptations.
The old party + Cecil take Orson and Shiris captive and tend to their wounds after the fight, and Slayn and his family are the ones who bring the adventuring goal forward: The Black Knight Ashram (from the first campaign) continues to cause trouble across Lodoss and is now seeking the Governor's Treasures, ancient artifacts from the Kingdom of Sorcery, each guardes by an Ancient Dragon (Red, Gold, Blue-Green, Black, and White). He's after the Scepter of Domination, an artifact that can force Lodoss to unite under his leadership/conquest, but he doesn't know which dragon guards it; thus, he's hunting all of them. He has already killed the White Dragon Bramd who lived near Zaxon and Tarba and was a friend of the priestesses. The treasure there was long since removed, he learns from the priestesses, sold off by the temple to pay for repairs and upkeep, but a treasure that would be sold could not be the Scepter, so he's continued in his quest. Slayn got word from the temple, and now they have a connundrum: the Black Dragon Narse lives on Marmo, and thus couldn't be the guardian or else Ashram would have the Scepter already. It couldn't be Mycen, the King-Dragon of Moss, as that Dragon's treasure is known to be the Staff of Life and was entrusted with the Temple of Pharis. So it's now down to the Blue/Green Water Dragon Abram who makes a lair near Raiden, or the most terrible of all five, the Red Dragon Shooting Star, who is terrorizing the countryside around Flaim and Raiden.
The party thus sets off but splits into two groups – Parn & Deedlit go with King Kashue of Flaim to try to kill Shooting Star, while Orson, Shiris, and Cecil go to Raiden to try to get to Abram before Ashram. Slayn and his wife initially shadow the new heroes, but are recalled by Parn & Deedlit mid-way due to trouble with the Red Dragon. It's in Raiden then, that the new party meet Maar, while looking for clues into Ashram's evil plans and for where Blue Dragon Island might be. Eventually, the parties will reunite and a big showdown will occur between Ashram, the dragons, and heroes old and new. Slayn has decided to entrust leadership of the new party with Orson, because his lack of emotions (when not berserk) gives him level-headed clarity, and also by adventuring with friends, he may rediscover his lost emotions sealed away by the spirit of Fury (that has possessed him since his elder sister died in the war from the first campaign).
This replay's adaptations thus took a long round-about way to get to the starting line of the Replay, and show different ways to form the circus party. The novel and anime take a "the adventure continues" approach using heroes from the past campaign to drive the plot forward but then pulls the old heroes away from the direct action so that the new heroes can shine. Eventually, the parties reconvene, and in the replay, the players of the old PCs get to run both their old character and their new character. This led to a bit of an aborted end to the adventure where the new characters got a bit sidelined; but the novel and anime deliver an emotional arc for the new party while keeping the spirit of both parties playing their roles in the conflict against Ashram and his "Bizzaro" party (a Dark Elf, two Pirate Mercenaries, a Dark Magic User, and a Neutral Priest of the War God, who wants to see great battles and wants to see how this plays out).
I'd note that Campaign 2 is also adapted by the OVA, but as per above, in a very abridged manner. Orson and Shiris are introduced instead in a side story moment in episode 6, in the midst of the first campaign's war (thus changing Orson's age as in other sources he's a kid during that war). They retain their characteristics, and the whole conflict about Ashram and the dragons follows on directly from the end of the 1st campaign, with Parn, Deedlit, Orson, and Shiris joining King Kashue's fight against Shooting Star and Ashram. The OVA then gecko-ends the story by a very loose adaptation of Campaign 3 with the final war against the Dark Island of Marmo.
The third campaign replay, adapted by Novels 6 & 7 and the remainder of the 1998 anime (episode 9-27), as well as a separate continuity manga that splits off from all of the above, starts again in Flaim, where Dark Elves stole one of the governor's treasures, and knight-in-training Spark failed to stop them and now has to lead a team to recover the treasure and also deliver a message from King Kashue to King Etoh of the Holy Kingdom of Valis (he became high priest, and then married the princess of the kingdom, this is explored in the non-campaign based Novel 5). Spark is important because one day he may lead his clan, the Fire Tribe that in years past warred with King Kashue's Wind Tribe. He may even be the successor to the Kingdom of Flaim, one day, as Kashue has no heirs. But because he's this important, Kashue's been keeping him on a tight leash, and thus he hasn't had the experience he needs to become a great fighter.
In this story, Lawful M Human Fighter Spark is assigned a team of mercenaries and volunteers from the capital Blade to accompany him on his quest: Lawful M Human Fighter Garrick (actually an undercover noble assigned by King Kashue to watch over Spark); Neutral F Half-elf Leaf Shamanist (who idolizes Deedlit and wants a love with a dashing knight like Deed has with Parn, and might develop a -thing- with Spark); Lawful M Dwarf Cleric Greevus (a priest of the War God but not the one from Campaign 2; note that with both Greevus and Leaf, we're no longer in Species = Class for nonhumans, as this campaign was already using a prototype of the Sword World RPG mechanics); and Assistant Court Sorcerer (Lawful M Human Magic-User) Aldo•Nova, who works under Slayn, is also responsible for the theft as his magic seals were the ones overcome by the Dark Elves. There's also Neese, a young teenaged priestess of the Earth Mother Goddess who has a special destiny and follows the party secretly until helping out in their first adventure in the city of Hilt and formally joining their party. In Hilt as well, they meet the Neutral F Human Thief Ryna aka Laina (translation discrepancy), who is saved by the party and Priestess Neese from a monster of the Dark Elves' creation. Neese's quest is because she's the sacrifice needed by Marmo's Wagnard to resurrect the Goddess of Destruction Kardis - alongside two of the governors treasures – one of these was the treasure stolen). So she seeks to face her destiny head-on rather than hide from it.
This third campaign's gathering of the party is a bit of a hybrid between the first two's lessons: gather some of the party on a clear quest; some may be motivated only by promise of coin from the benefactor, but others have strong desires of justice and/or guilt or responsibility to carry this mission out. But then also bring in other members of the party in Session 2 to fit into the team when they naturally would best fit the story. Ryna the Thief plays an important role on the team both from an adventuring standpoint and from her access to underworld services that this otherwise quite Lawful party would find. But given her less than Lawful personality and backstory, she wouldn't fit the original team setting off from Blade. Neese too would never have been allowed to leave if she had formally joined the party before they departed, as Kashue and Slayn and the like would rather keep her under their protection. But her willful and stealthful departure following the party allows her to join them because they don't have time or ability to break the party and bring her home. In addition, both she and Spark, as well as Leaf, have very clear ties to major characters of the past two campaigns. In addition to Kashue, Spark also idolizes Parn; Neese is under the care of Slayn, Aldo•Nova and the priestesses from Tarba; Leaf idolizes Deedlit and as a kid helped Parn and Deedlit out in a Deedlit-centric sidestory radio play/novel/manga). But furthermore, their respective quests run together not only in their goals but also thematically echo each other (Spark and Neese are both helicoptered by major NPCs due to their importance as heirs).
In a way, the third campaign is also very much different from the other two because most of the other two parties were nobodies when they started off; here the central protagonists are very much people invested in by the hero factions, and they have to not only overcome the BBEGs but also find their way out of the shadows of the heroes of the past. This is a great lesson to take for a game in a setting like the Forgotten Realms or Dragonlance or even Dark Sun, where the heroes of past campaigns and numerous novels might otherwise overshadow the protagonists and beg the question why we have his circus troupe of misfits on this quest in the first place, if there are great heroes like Drizzt or Elminster or Minsc & Boo wandering the countryside.
The 1990 anime OVA also notably has none of the 3rd Campaign Party's / 1991 Novels 6 & 7's / 1998 Anime & Manga's Heroes; it was written after the 3rd Replay came out so it followed the quest but reassigned the plot to Parn and Deedlit etc. Parn is the one who is fighting the Marmo empire, Deedlit becomes the thing that Marmo needs to resurrect Kardis, etc. But because of this, the final couple episodes are very un-D&Dish without much of a party whatsoever as it's got the heroes all doing their own things and being separated by the war. The 1998 anime adaptation in particular features a MEGA party of members of all 3 camapaigns' heroes headed to Marmo for a final epic dungeon with multiple concurrent final boss encounters. This would very clearly be modeled with Adventurers' League Epics, running on multiple tables. Given that Campaign 3 also reused mostly the same players, this wasn't the case back in the 80s game, but the adventure as shown in the anime would very clearly have had at least 2 tables running at once – Parn's party and Spark's party. A third table would be led by Shiris with a concurrent encounter but not in the same dungeon on Marmo. I'd note that while the anime is the more faithful of the adaptations of the novel, it still differs in some key ways, mostly because there was another 6.5ish novels set subsequently on Marmo that the anime was NOT inclined to adapt, and thus pulled key plot elements into their finale narrative instead.
I've used these four party-building situations as guides with my table, and Session 0 always focuses most keenly on the PCs' Traits/Flaws/Bonds. They do NOT need to all have a history previously, but making sure that the party has a reason to be together is the most critical part of maintaining a fun and focused campaign that doesn't go careening off the rails.
