Bioware Montreal developer Manveer Heir received a standing ovation at GDC this week for his speech challenging the prevalence of lazy, reductive stereotypes in games. He implored the industry to "stop being so scared", and start making games with more diverse characters in an effort to "reject stereotypes as a social responsibility to mankind".

The speech formed one part of this year's advocacy series of presentations, which explored problematic issues in gamer culture and the industry at large. The clarity and passion of Heir's speech in particular proved a stand-out moment, not just because of the issues at stake, but because of his mature, reasoned approach to stimulating debate around the depiction of gender, race and sexuality in games.

Heir backed up his ideas with research throughout the presentation. To begin, he cited a 2009 study, The Virual Census Representing Gender, Race and Age in Videogames, which analysed the primary and secondary characters of a large set of games and found that the elderly, children, black, hispanic and female characters were all uder-represented compared to the social makeup of the United States at the time. Heir also looked at the top 25 metacritic games of 2013. While half let players play as a woman, or an ethnic minority character, none facilitated both.

Worse, Heir noted that when ethnic minorities did appear, they were invariably depicted using clumsy and negative cultural stereotypes. "I don't think it's because devs are bigots," said Heir. "Rather, I would argue that this could be the result of cultural biases and unjust constructs that affect our culture, influencing how we make things."

He provided a few examples of negative stereotyping, turning first to the depiction of trans characters in GTA 5. "Here we find not people, but objects of ridicule" Heir said. "These women are wearing ridiculous clothing. The artists spent time drawing visible bulges in their skirts and underwear, and their occupation is that of a prostitute, which we are led to believe is degrading."

Heir also found black characters adhering to familiar athletic and criminal stereotypes. "For every nuanced interesting character we have, such as Lee Everett from The Walking Dead, we have a variety of more problematic and stereotypical characters, such as Sergeant Johnson, Tyler Miles, Sazh Katzroy, Franklin Clinton, Julius Little, Sam D, Mad Jack, Bo, Barrett, Balrog, The Witch Doctor, Mr. Po Po, Black Baron and, of course, Cole Train."

There are numerous studies to suggest that repeated exposure to stereotypes through media can change an individual's perception of their identity, Heir argued. By perpetuating stereotypes, designers play a small part in sustaining damaging ideas. Heir admits that games are but one aspect of this hugely complex social problem, but said the problem should be tackled wherever possible. "We can change this today."

He called for games to explore social issues in narrative, and beyond, in the game systems the player interacts with. He lauded Papers, Please for the way it puts the player into a moral quandary, and highlighted Assassin's Creed 3: Liberation, notable for letting players toy with the prejudices of 18th century New Orleans. In Liberation, you play as Aveline de Grandpré, an African-French assassin who can adopt different personae, like an upper class lady or a slave, to manipulate the behaviour of passers by.

Heir was talking to designers in this instance, but these ideas have been meeting resistance in comments threads, forums and on Twitter for a while. The quest for better representation in games is an emotive subject for those seeking it, but this isn't a push against organised ideological resistance to diversity, but rather apathy. Some players will suggest they just want to dip into a game for a few hours without being drawn into a treatise on sexual politics. For these folk, talk of exercising one's "social responsibility to mankind" can seem lofty, end egotistical. They can feel targeted for enjoying games that star stereotypical characters. There's a fear that a push for diversity will result in bland tokenism. These concerns are often met with anger, rather than reasoned argument.

That needn't be the case when the case for better representation is so logically sound. Heir's strongest point was his declaration that over-reliance on stereotypes is simply "boring", and on a higher level, contributes "to the creative stagnation in our industry". No matter what your personal politics might be, a greater variety of characters means more complex relationships, which means more mature and interesting games. It needn't be about ideology, it's just common sense.

There's a growing, increasingly organised group of developers and players seeking to challenge the industry on issues like representation from without and within. I find that encouraging, because I hate boring games, but I worry that the language some proponents use to frame the debate does more harm than good. Even Heir's speech revolved around notions of social "justice" - a loaded word. The sort that can inspire a standing ovation if you're not careful. By positioning one's self a conduit of justice, you declare those that support the systems you oppose are perpetrators of injustice, which puts them in the absolute moral wrong. It's the language of the crusader, a figure that can't be reasoned with. Referring to supporters as an "army" also implies an unhelpful oppositional relationship with those his supporters should seek to persuade. The language designed to rally allies simultaneously obliterates the space where the conversation needs to happen with those that disagree, and those who haven't fully considered these issues before. That's the only space that really matters. That's where minds are changed.

Heir's speech got a lot right, however. It was an important and powerful moment this year because, ultimately, it wasn't about storming barricades or attacking individuals. It was a message from one developer to a room of developers, asking everyone to go away and raise the issue with colleagues in their respective organisations. It was a well-reasoned, well-researched and impactful, and took pains to avoid falling into some familiar traps. It wasn't a drum-banging speech for those already in complete agreement. It didn't, as these things sometimes do, reflect more on the author than the issue. The anger behind Heir's words made it an energising listen, but the speech didn't accuse or condescend, and didn't draw battle lines. That's exactly where the debate needs to go. Nothing changes if everyone digs trenches.