The success of The Dark Knight Rises has proved that three isn’t always a crowd, and with a little care and effort it’s entirely possible to bring a film series to a successful close with an equally powerful conclusion. It’s all the more noteworthy in the fact that this universe wasn’t fully mapped out when the first film was conceived.

Something which has undoubtedly benefitted Nolan and his writers was the time they had in crafting each tale and making sure that plotlines and characters arcs were effectively wrapped up (although as you read this, numerous blogs out there are picking apart the minor inconsistencies and contrivances). Bane’s back-story is factored into the story in a wholly satisfying manner, and even with a leisurely two decade gap, George Lucas couldn’t weave together the strands of his universe into a similarly coherent and emotionally rewarding fashion. As case studies, both sets of Lucas’ films offer perhaps the best and worst examples of how to construct a trilogy, but the form exists in many different guises, some more successful than others.

Sometimes a series can take a severe nose-dive after two great features, where either studio invention or a genuine sense of what made the first two work is sorely absent (Spider-Man 3, The Godfather Pt III). Then there’s ‘The Matrix effect’, where a first film starts off incredibly promisingly, building a solid mythology which manages to hint at tantalising future developments, only to seriously fudge things with Part’s 2 and 3 (the films in question are still a painful memory, even after almost a decade later). It’s doubtful even the more ardent apologists of the series would clear a whole day to watch those films back-to-back, and for a franchise which once offered a potentially classic trilogy of films, they’re now more synonymous with that permanent £8 red-stickered vast surplus of stock, stacked Jenga-like, in HMV’s across the land.

Trilogies are sometimes happy to leave their world unexplored, and merely offer a continuation (sometimes with minimal deviation) from the original, which usually results in diminishing returns (RoboCop, Jurassic Park, Predator, Beverly Hills Cop, Blade, the ‘Ocean’s’ series). While all three of the Bourne films (soon to lose their status as a trilogy) fall somewhat in this category, containing similar action and character beats throughout, their success lies in creating that ongoing journey of discovery for the central protagonist, which drives each narrative and keeps the audiences invested in what’s going on. The Transformers series, one of the more ugly and cynical examples, attempts to make revelatory leaps with each film, but the ill-conceived back stories cooked-up offer little intrigue and fail to establish a genuine sense of continuity throughout.

Some slunk off to the land of DTV after the first or second feature (The Addams Family, Disney’s Aladdin, From Dusk Till Dawn, The Lost Boys), existing as a mild curio for fans of the originals, and little else. It’s inconceivable now to think that could have been the fate of the Toy Story series. Although the films have now taken their place amongst the most-cherished trilogies of all-time, Disney initially asked Pixar to make a direct-to-video sequel to the original, only to be convinced otherwise after seeing the level of quality Lassiter and Co. were churning out (presumably that magic was missing for the execs behind Behind Enemy Lines II: Axis of Evil on their set visit).

There are celebrated trilogies which don’t necessarily fit that mould and exist essentially as two-parters, with the second instalments representing a bigger budget remake of the first (Sam Raimi’s Evil Dead films and Robert Rodriguez’s ‘Mexico’ series). It’s to the filmmaker’s strengths that these two (Evil Dead, in particular) are wholeheartedly embraced by fans and viewed as continuations, despite their structurally-illogical paths.

The Back to the Future series offers a different take again, and even if the second part ranks below the wild west Streampunk shenanigans of Part III for some, its paradoxical premise sets it aside from most trilogies. Beginning as a thematic and visual retread of the first film, when the action returns once again to the 1950’s, we’re offered that fascinating opportunity to witness events of the first film from a peripheral vantage point. It was an audacious move for director Robert Zemeckis at the time and deserves recognition for that avoidance of playing by the rules.

It’s clear that the more successful trilogies offer something akin to that three-act structure of a feature film, albeit in an elongated form. It’s interesting to note that the adaptation of properties which initially adhere to that formula in book form (the Twilight and The Hunger Games series) are now being remodelled to accommodate a four-part arc in order for the studios to milk their staggeringly lucrative cash cows for all they’re worth.

Ironically, for someone who managed to fashion one of the most successful trilogies of all time from source material of the same length, Peter Jackson is now crafting his forthcoming adaptation of The Hobbit (a pretty episodic book) into a new trilogy. God knows what New Line might have done with The Lord of the Rings and all that supplementary material shot by Jackson, had the films gone into production after the financial benefits of extending a three-part series was realised. Gollum may have become as regular (and as recognisable) a Christmas fixture as turkey and crackers.

But what of those films which look like they were custom-made to tell a larger story, but failed to materialise as a second entry? Having established Bruce Willis as a Super(every)man figure at the end of Unbreakable, there was the scope and real-world vision (since mined by TV’s Heroes) which could have easily been sculpted into three parts. Could Willis’ character have gone through a similar arc to that of Batman and other superhero films by losing his way in the sequel, only to come storming back in the third? Could we even see a return to this world if Shyamalan strikes out for the fourth time with his Pursuit of Happyness in the Cosmos (aka After Earth) next year?

In this age of minimum risk-taking where studios are more and more looking at fostering as close to a box office sure thing as humanly possible, trilogies (and beyond!) are destined to become even more commonplace.

It remains to be seen if Hollywood can stick to the lessons learned from Warner Bros’ handling of the Batman property, and can offer a modern, savvy audience something much more imaginative and rewarding than a numeric or colon stuck to the end of the title.