Based on my recent research and considerations of the roguelikes in the videogames scene in 2018, I just published two new articles into Temple of the Roguelike. Both originate from my talk on the Roguelike Celebration 2017.
The first one is “A short history of the “roguelike” term“, which expands upon my previous article “On the Historical Origin of the “Roguelike” Term“, covering the events after the term was established and the subsequent confusion.

The other related article is What is a Traditional Roguelike; after 10 years of trying to come up with long lists of definitions, I narrowed it down to 4 critical aspects I think traditional roguelikes should keep:
1. Permanent Consequences
The outcome of any action you take into the game cannot be rolled back by reloading a saved game (including death).
This encourages both careful tactical play and long-term strategies and planning and increases the excitement of advancing through the procedural content generated by the game.
2. Character-centric
The player personifies a single character into the game at a time, this is in contrast to both a.) games where the player doesn’t control person-like characters directly (for example puzzles) and b.) “god” style games where the player is an abstract entity creating and controlling multiple discardable “units”.
Besides providing a common, shared base format for the Traditional Roguelikes, being character-centric helps the player establish a strong relationship with the individual characters, increasing the impact of the permanent consequences.
3. Procedural content
Increases the replayability of the game by having most or all of the world be generated by the game for every new gameplay session.
In addition to providing an incentive for players to dig into the game, procedural content serves as a tool to prevent the player from being frustrated by the harsh effect of permanent consequences, having to start gameplay session from scratch frequently.
4. Turn Based
Gameplay is similar to a board game where you can think your actions carefully, having infinite time to reflect on your available options to face the situations that the game presents you with the resources you have at hand.
This is relevant given consequences are permanent, and the intent of the game is not testing how quick the player can take an acceptable decision but rather challenging him to think out the best move he can make in critical scenarios.