Rise above the hype
On the Media's Breaking News Consumer's Handbook is a frank, concise set of guidelines to remember whenever you're trying to parse developing events from the modern diaspora of information sources. Of course, confusing, conflicting sources aren't nearly as common in video games, where much of the story proceeds in an orderly fashion based on whatever information game companies decide to dole out.
Drawing gameplay conclusions from a CGI trailer is folly
Pre-rendered trailers have been a fixture of video game marketing for decades, but up until recent years they've been more of a proof-of-concept than a potential source of confusion. Unfortunately, as gaming visuals creep closer and closer toward photo-realism, it's become easier to mix them up with actual scenes of gameplay, or at least to conclude that they're real parts of the game with an extra layer of post-production polish.
Don't get swept up in the little visual details
Even if you're certain that you're seeing a game in motion, don't assume it's the game you'll actually get to play. Much can change between an impressive reveal video and release, as was infamously demonstrated by Watch Dogs: the actual game, which released in May 2014, was notably less visually impressive than the live demonstration Ubisoft gave two years earlier.
If the trailer lasts more than 1:30, you can safely skip to the last minute
Marketers love to frontload trailers with scene-setting material: expository voiceovers, extreme close-ups on impressively rendered woodland creatures, slow panning shots of the hero's new and improved equipment. That's all fine if you're already invested in the game and are eager to see every little detail, but for everybody else, it means a lot of sitting around and hoping the interesting part will start soon.
If it's not a yearly sequel, add six months to the release date
It might feel like every big game of this generation has missed its release date by at least a month, but that isn't the case. Series like Call of Duty, Madden, and Assassin's Creed have a strict yearly schedule to adhere to, and while they might shift a few weeks from time to time, you can usually count on them to release like clockwork - relatively speaking. But if the game in question isn't part of an annualized franchise, then, well, don't go planning important life events around its release date.
'Acclaim' can actually tell you a lot
Trailers will often throw out a few dozen quotes with positive-sounding phrases like 'breathtaking' or 'a must-play' in rapid succession, trying to give you the impression that the game has received unanimous praise from critics. But it's a good idea to apply some skepticism to whatever marketers tell you about their product, even when they quote a publication or person you trust to make their point.
Just because a trailer has a great tone doesn't mean the game does, too
Rather than setting up important characters or events, some trailers are intended more to establish a certain tone. Dead Island's famed CGI trailer did little more than tell you that this is a game on an island with zombies in it, but its shocking imagery and reverse-spliced chronology did a phenomenal job portraying a bleak, hopeless atmosphere. Unfortunately, Dead Island's zombie-slaying loot-em-up action did little to follow through on that tone. That's an extreme example, but many other games have had their thematic ambition (or lack thereof) shown up by their own trailers.
The mute button was made for unwanted music
Gears of War's "Mad World" production remains one of the most surprisingly impactful trailers ever made. It's attracted plenty of imitators since it first aired in 2006, many of whom took cues from how it introduced Marcus Fenix as both vulnerable and an ass-kicker, and the world of Sera as a place of broken beauty. Unfortunately, not every unlikely game-and-music pairing works equally well.
Stage stunts are just there to get your attention
You can only watch so many gun-wielding characters wage a desperate war against a seemingly insurmountable enemy before they all start to blend together. No matter how well-made they are, trailers released in and around E3 all have a difficult task in holding on to your attention. Rather than distinguishing their games solely through unique gameplay snippets or impressive visuals, some companies choose to add a little something extra around the edges of their presentations.
Everything is subject to change
By their nature, work on big, fancy trailers has to begin many months before their planned debut. But since huge changes often come about in the span of weeks in game development, that means promotional materials may end up not being completely accurate to the current state of production. Unfortunately, you can't push back the release of an E3 trailer the same way you can push back the actual game (or else it wouldn't be much of an E3 trailer).
