For years now, continuity has been a particularly divisive word. It's one of the subjects that can be practically guaranteed to split opinion between the more traditionally minded superhero readers and the audience that flocked to New Marvel.

Broadly, the traditionalists think continuity is fantastic. They talk with wistful longing of the happy days when Thor would break off from what we was doing, simply to gratuitously acknowledge a completely unrelated Power Pack story. Some of them, poor souls, actually miss the days of line-wide crossovers. But most simply preferred the sense that everything was happening in the same universe. For them, it added to the suspension of disbelief.

The other point of view comes from audiences and creators who don't identify themselves as fanboys and don't read stories as forming part of some multi-decade historical sweep. They prefer their stories freestanding and self-contained. They see no reason why a perfectly good story idea should be discarded merely because it contradicts something that's come before, and they don't want to see creators deviating from their agenda solely to reflect what other people are doing. After all, that's writing by committee, and (US sitcoms aside) writing by committee is almost invariably terrible.

And everyone tends to fall into the trap of using "continuity" to mean "continuous interaction between different titles". Strictly speaking, it ought to just mean mutual consistency and the absence of contradictions. You can achieve that without any real interaction between titles. Even at their most continuity-minded, Marvel and DC have always featured a handful of titles off on the fringes of continuity that have drifted gently about their business, completely unaffected by anything else around them - simply because they were so far removed from anything else that the question of mutual consistency never really arose. Titles set on other planets, for example.

'Some readers prefer the sense that everything happens in the same universe.' Problems arise because publishers attempt to have it both ways. In so doing, they end up with an awkward compromise approach that satisfies no one. Both Marvel and DC have always recognised the strengths of their shared universe concept. They've spent years training readers to love it, so it's hardly a surprise that so many of them do. Marvel even go out of their way to mention the Marvel Universe in their annual report.

The advantages of shared universes are straightforward. They provide a common pool of concepts, characters and settings. Between them, the various Marvel and DC titles ought to be able to define a fantasy version of the world that is richer and deeper than any individual title would manage. Done properly, it should result in a world that's more believable and, in many ways, more fun.

This really has little to do with the nitpicking approach to continuity that gets worked up about insignificant contradictions with long-forgotten stories. It's more about providing a coherent and stable backdrop against which stories can take place.

Once a writer has invoked that backdrop by placing their story in the Marvel or DC Universe, much the same considerations apply as to any choice of backdrop. You don't have to achieve absolute accuracy to make successful use of a shared superhero universe, any more than you need to achieve full medical accuracy to write a successful episode of ER - most of the audience won't know the difference, once you get beyond a certain level of surface credibility.

But you'd better get that surface right. If destroyed cities and dead characters are going to reappear, or characters are going to forget major storylines that are still in the readers' minds, then readers will understandably be jarred out of the story, just as if you wrote a medical drama where broken legs heal in three days.

'Publishers attempt to have it both ways, and end up with an awkward compromise.' Creators shouldn't complain about this. They're the ones who invoked continuity in the first place by setting their story in the shared universe. If they didn't want to deal with the baggage, fine - but then, don't use the shared universe. It's not like you're making any use out of it.

Except, of course, it's not that simple. Because when established characters appear in stories set outside their core universes, sales tend to be less than impressive. This is hardly surprising. Readers have been trained over the years to regard the core universes as 'real', and to think in terms of overreaching long-term stories. The corollary is that stories set outside continuity do not feature the 'real', characters and are intangibly second-rate.

The irony is that stories don't actually have to have any effect on wider continuity - the mere fact that they're in continuity is enough. Look at ORIGIN, a series set in the late nineteenth century. Despite a couple of token references, it would be fair to say that the book has been almost completely inconsequential in terms of later Wolverine stories. But that didn't stop it selling - and it's hard to believe that it did so by tapping a hitherto unnoticed audience for costume drama. It sold because it was The Origin of Wolverine - not merely a story that might arguably be the origin of Wolverine, possibly. (They tried that approach with TROUBLE, and look where it got them.)

Because of the way the audience has been trained to respond, continuity still means money. So commercial pressures lead publishers to fudge the issue. Stories with glaring continuity obstacles will be blithely asserted as canonical, regardless. On occasion, stories that aren't in continuity at all will be released without actually clarifying the point, in the hope that nobody will notice. The current PUNISHER series appears to be out of continuity, for example (it gives a completely irreconcilable version of Microchip's history). God only knows whether ROSE AND THORN is meant to be in DC continuity. I spent half an hour trying to work it out, and I was left none the wiser.

'Readers have been trained to regard the core universes as 'real'.' More problematic are the stories that simply claim their place in the shared universe and then proceed to ignore it. The benefit in having shared universes lies in their broad consistency, and in working as a stable, common setting.

In recent years, some Marvel characters have developed an annoying habit of making guest appearances that simply refuse to acknowledge any that's happened in their book in recent years. The Hulk always makes guest appearances with his savage personality, which is some two years out of synch with events in his own title. Thor continues to appear in other titles as if he'd never inherited the throne of Asgard, which is getting on for three years ago now. These aren't fine details, but matters of broad consistency, and it's clear that there's a policy decision to ignore them. At that point, the shared universe and the benefits that come with it start to fray at the edges.

DC has always had a particularly schizophrenic approach to these matters, as far back as the Crisis. The Crisis was a bizarre exercise in demolishing the existing continuity (on the basis that it had become unwieldy); asserting that a streamlined version still applied (and that history was broadly valid); and then spending the next few years blithely ignoring everything and throwing everything into confusion. Far from streamlining anything, the Crisis ended up opening the floodgates to such enormous degrees of revisionism that the credibility of the DCU as a shared universe was crippled. To this day, Hawkman is known more as the poster boy for continuity gone wrong than for any actual story he's ever appeared in.

Over the following years, DC managed to iron out most of the major kinks. But that hasn't stopped them approving John Byrne's baffling pitch to reboot DOOM PATROL from scratch, and put them straight back into the DCU. This involves deleting decades of stories, including some very recent material. But it can't work. In order to get the New Doom Patrol into the DCU in the first place, you need to drop a bomb on all the relevant areas of DC continuity. They'll gain no benefit from the consistency of a shared universe because they're a walking example of inconsistency.

Marvel and DC both seem confused as to exactly why they have a shared universe - at least as a storytelling device rather than a cash generator. Of course, there are plenty of good stories that don't fit into a shared universe. The solution is - duh - don't put them in the shared universe. Retrain the readers. The current approach is just to shoehorn everything in regardless - but what's the point of that?

Paul O'Brien is the author of the weekly X-AXIS comics review.

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