It’s been so long since Doom first slipped into floppy disk drives the world over that there’s an entire generation of console and PC players out there who’ve never even heard of Doom, let alone played it. And yet, despite its age, this dusty old relic lives on every shooter that’s come and gone since. Every single First Person Shooter that’s taken over the world – or failed miserably – can doff its cap to Id Software’s seminal piece of software.Not many games can call themselves genuine milestones, but Doom can claim such a title with confidence. For its 25th anniversary, we look at how Doom helped change PC gaming forever.There are just so many elements that programmers John Romero and John Carmack helped popularize back in 1993 – concepts that laid out a fundamental blueprint not just for shooters, but for western videogames as a whole in the decades that followed.The use of immersive 3D graphics at a time where games were still resigned to flat 2D sprites in 16-bits. It helped set the groundwork for networked multiplayer matches. It promoted the use of mods (or ‘WADs’ as they were known back then). Even how it deftly juggled everything from…