Games where each playthrough is unique: levels are randomly generated, enemies and finds are different each time, and death usually means starting over. You have to learn from mistakes and rely on familiarity with the rules rather than a memorized map. Modern examples include The Binding of Isaac, Slay the Spire, and Noita.
In a roguelike, everything starts from scratch after death, while in a roguelike, some of your progress remains — new skills, characters, or upgrades between runs. Therefore, roguelikes are more lenient.
Where to start if you've never played?Starting with shorter games with clear rules: card roguelikes like Slay the Spire teach you to think ahead, while action roguelikes like The Binding of Isaac give you a feel for the genre in a single evening.
All roguelike games on the site are available for download via torrent — sort the list by rating, size, or year of release.