Drop Duchy is an unholy fusion of city builder, roguelike deckbuilder, and Tetris, and you can try it for free right now

Roguelike deckbuilders rampage across Steam. They grow and replicate without impediment, swallowing up every other genre they encounter to spawn new hybrid mutants. We are doomed and all is lost. Or to put it another way: Duchy Drop is a roguelike deckbuilder-meets-city builder-meets-Tetris.

Each run consists of a series of battles against… rival duchies, I guess? These play out like Tetris, though without the need for quick thinking—you have as much time as you like to place each block. The blocks themselves represent terrain and buildings, and though completing a line doesn't clear it, it does extract all resources from those tiles.

The goal is to arrange things as advantageously as you can. A farm, for example, is a block that will turn all plains around it into fields, while a ranger's station generates soldiers based on how many forest blocks it's connected to. Synergies soon start to suggest themselves—for example, a wood clearer will turn forests into plains, which a farm can then exploit, creating the perfect area to place a watchtower, which gains bonus soldiers from plains and even more from fields.

What are all those soldiers for, you may ask? This is where Duchy Drop's most interesting twist comes in. The opposing nation throws its own military buildings into the pool of blocks, but it's you who gets to place them. While trying to place your own buildings for maximum effect, you're also trying to deliberately place enemy buildings as badly as possible—encircling a training ground in useless forest, or clearing all the trees away around a ranger station. You can even swap one enemy block into your reserve slot and avoid ever placing it.

Once all blocks have dropped, battle begins in earnest—though it's a simple affair. Soldiers stand on the blocks that generated them, and you have to drag one into another into another in a long chain. Friendly groups merge, opposed groups fight, and you keep chaining into all have been resolved. It's primarily a numbers game—my 10 swordsmen beats the enemy's 5, taking a few casualties as they go—but there's some simple rock-paper-scissors to account for too, with arrows beating axes, axes beating swords, and swords beating arrows.

As you progress through these battles, you gain new buildings, and resources gained can be used to buy more or upgrade your existing ones—so while 'terrain' blocks are based on the battlefield, your buildings effectively form your deck. Only a certain number can be brought into each battle, though, allowing you to make strategic choices based on the lay of the land. You'll be forewarned, for example, if an area contains more of one terrain type or another, allowing you to specialise towards that type or try to counter it.

The demo ends just as this multi-layered tactical tangle is starting to get really interesting—with a boss fight called The Wall that devilishly restricts how high blocks can be placed each turn—but there's definitely serious potential here. Part puzzle, part RPG, part strategy game, it's a fascinating experiment, and it's easy to see how more terrain types and buildings in the full version could result in something wonderfully brain-bending. Give it a try for yourself—the demo is part of Steam NextFest, so you can play it for free before March 3.