This probably feels like a bit of an odd place to start, but Warlock: Dungeons & Dragons isn't Fable. Yet, when I sat down to watch developer Invoke Studios' Gamescom demo of Warlock with no real idea of what to expect, it was the first thing that popped into my mind. Not because of its striking fantasy landscape - crooked hovels huddled awkwardly amid a vast sprawl of ragged coastline, jagged mountains, and, in the distance, an imposing tower looming over all - but rather the moment early on when Warlock's warrior protagonist Kaatri enters the town of Crickshank and is immediately welcomed with a couple of fruity insults from the locals.

Admittedly, "Well, well, look what the mists dragged in", isn't quite as spirited a greeting as "Arseface". But I couldn't help wondering if Darkon - Warlock's setting, and an area of Dungeons & Dragons' Ravenloft that's slowly being devoured by fog - was aiming to be a similarly reactive sort of sandbox to Fable's Albion. The answer, it turns out, is not quite. Rather, as Invoke general manager Dominique Guay tells me, Warlock's open world is reactive in its own way. The goal here isn't to "create a world that's living without you completely", but the team still wants to make it feel alive. Guay points to the end of Warlock's Gamescom demo as an example, where Kaatri stumbles upon an already unfolding skirmish and can - if a player decides to - join in.

For Invoke, though, the real goal is to put Kaatri's magic - which she acquires after making a pact with her patron, the witch Tasha, in effort to find someone she's lost - at the heart of it all. "Our main focus is first that the world be reactive to your spells and magic," explains Guay. "That's the baseline we're interested in. We were really drawn to magic as a way of expression, as a way of being creative as a player." Magic is such an integral part of Invoke's vision for Warlock, in fact, that it's the first thing the studio shows off in its Gamescom gameplay demo, even before offering a wider look at the world.

Early on, Kaatri is seen wielding her borrowed magic to navigate some brambles blocking her path. She could simply smash through them with her sword, but instead we see her using a cantrip known as Tasha's Leash to snare a nearby lantern and hurl it at the prickly undergrowth, causing it to erupt into flames. Using Tasha's Leash on the resulting inferno would pluck a makeshift fireball into being, but instead, we see her grab some water from a nearby pond and use the shimmering aquatic bauble to douse the flames. This leaves behind a pool of oil that can be similarly commanded - perhaps to throw at enemies, which can be ignited in turn.

It's a simple display of Warlock's magic loop, and as the demo continues, there are hints of how Invoke intends to build on this foundation as play goes on. Down in Crickshank's fog-gripped depths, for instance, we see how Tasha's Leash can interact with a second spell, Black Tentacles. Alone it has basic combat utility, but Kaatri can also conjure a grasping tendril then use Tasha's Leash to yank masonry off the walls. Combining the two creates an impromptu platform she can use to safely cross the deadly miasma.

But there's plenty more in Kaatri's magical arsenal. Misty Step allows her to adopt a non-corporeal form and wispily teleport through grates or around monsters. Eldritch Blast, meanwhile, can obliterate objects and enemies from a distance. More elementally minded players can use wind to push targets, summon rain, or conjure lightning. And in another example of Warlock's synergistic loop, the latter's potency and reach is improved when used in the vicinity of conductive material such as, yes, water. "We didn't want just 'this spell does 10 damage, this spell does 100 damage in this size in that area'," Guay explains. "We want players to be able to improvise, to learn, to be creative with these spells, and so we started from there." In fact, many of the spells are "optional", only found by thoroughly exploring the world.

Warlock isn't solely a game about magic, however, and Kaatri's warrior roots means she's adept at melee combat too. Players are able to equip two weapons at once, in a primary and secondary configuration, with Guay pointing to the likes of swords and warhammers; some single-handed, others requiring two. Weapons, like magic, are upgradable, and the goal here is to give players rich customisation options that continue across armour, gear, enchantments, talismans, and more - the emphasis being on bespoke pieces with their own traits and looks, rather than, as Guay puts it, "just like stats and numbers."

As for the combat rhythm this split between magic and melee creates, Guay explains: "The reality is kind of a dance where you go to spells, you set things up, you go into melee ... then back and forth, [and this] flows well because the spells are directly accessible in the controller." All this together gives Warlock an intriguing foundation, and could provide a distinctive flavour to its action as Kaatri prowls the open-world.

And, honestly, it's the world I'm perhaps most curious about. For the D&D fans out there (if I'm honest, I barely know the difference between a cantrip and a cantaloupe), Invoke is promising plenty of connective tissue, from a tone that fits the "darker, more mature side" of D&D's Domains of Dread universe, to familiar spells and enemies. But perhaps more interesting is the team's pedigree: Guay and others at Invoke are Ubisoft veterans, and - having worked on the likes of Far Cry and Watch Dogs - know their way around an open world. Invoke's vision for Warlock though is a bit more ambitious than Ubisoft's familiar icon-spattered open-world formula, and Darkon is instead being built in the spirit of D&D.

As Guay puts it, Invoke is keen for players to be the driving force behind their own adventure. "We wanted to really make the game, first and foremost, about exploring a world instead of just following a waypoint around," he says. "We want the player to truly go out there, visit places, be curious, uncover secrets." To that end, Darkon is "pretty large", albeit certainly nothing like - to use Guay's example - Crimson Desert's world. Going too big, he argues, would be a "disservice" to Warlock's focus on exploration.

"We don't want you to have to travel for 15 minutes to find a new location," Guay elaborates. "We want you to be always within like a minute, a minute and a half, of another cool place." Density and diversity appear to be the watchwords here, with Invoke wanting to create "different and crazy environments" while still having the space to transition between them naturally. "It's smaller than those huge worlds," Guay says, "but it feels like an open world. You can get lost in it." And even here, it all comes back to magic.

"We're not making a Metroidvania game," Guay continues, "but to a degree, you'll want to acquire more spells to reach more places. It's not binary like a Metroidvania would be, but there's an element of that in … your ability to traverse terrain and reach new places, [and in] the monsters and the challenges you're gonna have to deal with."

Kaatri's "grim personal quest" might form the backbone of Warlock's structure but Guay says there are "multiple ways" to approach the points that make up her story, "so it's going to flow depending on how you explore the world. That forced us to accept that a lot of our content was optional, and we're okay with that ... we're trying to make sure [we don't] force you down a very narrow critical path." And, crucially, the route forward isn't necessarily an explicit one.

Invoke's aim, says Guay, is to create a "cohesive" world, and as the fog of war slowly lifts through exploration, players can expect to uncover the likes of dungeons, mines (useful for acquiring iron ore for upgrades), and settlements, each with their own "specific, unique mood". However, "it's not like there's an exclamation point [on the map]," notes Guay. "You'll have hints on what you should work on next or how you can further your main quest, but ... you're going to have to listen to people, ask questions, investigate.

"We want to have stories happening in the world instead of us telling you a story," he continues. "Most of our content is just there in the world ... You'll find a cool-looking location, you'll explore it ... and you're like, 'What is this, what happened here, what's going on?' ... And as you do, you'll stumble on side quests which have multiple entry points ... Maybe you'll find a poster or talk to someone [and] you can decide to opt in or out."

Embarking on these stories might involve more combat, but magic also resurfaces as a tool for "open-ended" puzzle-solving. "We want you to be creative with your magic," Guay says, "so it can't be just one solution to a thing." And while side quests are intended to accentuate the narrative, exploration also provides a throughline of steadily increasing power: "Finding new spells, finding raw magic that allows you to upgrade [them], finding rare artefacts, gears. So the kind of adventures you'd expect to do in Dungeons & Dragons."

Invoke is, though, also keen to manage expectations around what it isn't trying to do. Despite coming on the heels of Baldur's Gate 3, Warlock isn't intended to be a game where you can shape Kaatri's story through the likes of conversation trees and dialogue choices. "We're being very clear on that," explains Guay. "Kaatri is a written character, so it's not like you can play evil or good Kaatri. Nothing like that. The main narrative moments you're going to go through are written down, and you're going to go through the same moment as someone else." And you shouldn't expect to be accompanied by a ragtag adventuring party, either.

Although there are "definitely allies you'll make along the way, kind of her found family", the moment-to-moment focus is on Kaatri and her imp companion Skev - a character who can also be spotted in Warlock's Gamescom demo. Skev has gameplay purposes during the adventure - his upgradable skills including lockpicking and distracting enemies during combat - but he's not just a sidekick; he's also intended to be "his own character with his own motivation." As the imp advisor to the disappeared ruler of Darkon, Skev, like Kaatri, is looking for someone. "So there's an ongoing story there of how their relationship grows."

And that is pretty much everything Invoke is saying about Warlock right now. In many ways, it's a familiar proposition with its sprawling dark fantasy open-world, but - having walked into its demo with no foreknowledge, no expectations, and, yes, a fairly minimal understanding of D&D - I walked away impressed with what Invoke is trying to achieve. Of course it's not Fable, but Warlock's own take on reactivity - the focus on synergistic magic that permeates everything from combat to puzzle-solving - is an intriguing one. And I'm curious to see how far Invoke can push it, and how fresh it feels, when Warlock: Dungeons & Dragons launches next year.