About whether DF Fortress mode is roguelike, for those who like to split hairs, we should clear up some confusion about what "real time" is. If you can stop the clock and queue arbitrary actions, your game is not real time. Dwarf Fortress is not real time. Starcraft is real time. Mario Brothers is real time. Dwarf Fortress allows you to advance gametime one time quantum at a time and allows you to stop time altogether and issue arbitrary commands during the use.
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Look, I don't debate that Fortress Mode isn't real time, but I don' really feel comfortable calling it turn-based either. I'd argue that most of the time is spent running the game instead of having it paused, but what that makes it is really up for discussion.
I think we could probably agree that Dwarf Fortress can be played in a turn based way in almost exactly the same way crawl and angband can though. Of course, no one would want to, but the mechanics for doing so exist.
There are two things about Fortress mode that mark substantial deviations from the usual roguelike approach: Controlling multiple entities and doing so via issuing work orders that are carried out by various dwarves according to who's available and so forth. You guys make it easy on me by saying roguelikes no one's ever played or heard of ("7DRLs", etc.) count as expanding the genre, so I should say I know of at least one roguelike that allowed you to control a party of characters -- it was an angband variant and the author did not come up with a convincing system of control (unsurprising for an angband variant maintainer). I'm sure there's a ridiculous thread to be had about whether this angband variant is roguelike, please spare me. The point is, once you allow multiple entities, which is not unprecedented in the genre, it's natural to have a command set with emphasis on performing tasks that would take a number of turns and therefore hundreds of keystrokes in a traditional roguelike.
Again, this challenges the typical definition of a roguelike. For many people, roguelike also means you control one char, and you control it directly. Both of those have been subverted over the years - there are multi-character roguelikes, yes, and there is at least one game with indirect control. I don't deny that.
Yeah, it's definitely a departure from established conventions, but not so radical as to be unprecedented or, in my view, disqualifying.
But if you look at the existing roguelikes, both established ones, small ones and 7DRLs, 99% of them are about exploration and hack&slash, either in the stereotypical dungeon or some other hostile environment. DF, in contrast, is a game about building a base and caring for dwarves. The gameplay is vastly different from almost every roguelike I know. It's much more like a 4x game.
As an example, let's take a look at my favorite TBS game of the old days, Civ 3. It has a world that can be and often is randomly generated, it is turn-based with direct control, it is grid-based (good old pseudo-eight-directions like roguelikes have it), it's non-modal, has several solutions for problems (as you would expect in a roguelike), you have to manage resources, no rule difference between player units and other units, it shows you the numbers and is tactically complex. So right out of the box it fits at least more than half of the points of the Berlin Interpretation (which of course isn't perfect, but a good compromise between different people's idea of a roguelike). The problem is that Civ 3 is a turn-based strategy game and no one ever will call it a roguelike.
I agree with what you say here about Civ 3 and the so-called "Berlin interpretation." But this just shows that the Berlin interpretation is absurd. For example, "ASCII based display" is not a low value factor, unless you're writing a tile based game for a handheld and trying to call it roguelike. Likewise, the Berlin definition makes no mention of a fantasy setting, despite that being a clear common denominator among the canonical examples of rogue, larn, hack, moria, nethack, crawl, ADOM etc. Why might that be? Because one of the handful of people in attendance at some summit was promoting a sci-fi or trademarked commercial video game themed "roguelike", I'd wager.
The definition held up as the gold standard fails to clearly separate roguelikes from other genres while at the same time failing to take into account basic commonalities between the classics, old and new. Yet, as you say, the according to Hoyle roguelikes really are clearly different from any civilization game and no one would call Civ 3 roguelike. It's ridiculously easy to poke holes in the Berlin "definition", so why even bother with it?
On what you say about exploration and hack and slash, this is true to some extent. Dwarf fortress can definitely be played in a way that has not a lot of monster killing and not a lot of looking for things or going places. Of course, mining and excavating, finding caverns and eventually hell are forms of exploration. I think the more damning issue is that the items you collect in the process are primarily raw materials (minerals, plants, etc.) rather than the traditional prefabricated loot of roguelikes and you're exploring/striking the earth, not a fully formed dungeon (although the caverns are dungeon-like).
On the other hand, it's obvious that Dwarf Fortress is heavily influenced by the roguelike tradition. The objection to calling it roguelike can only be that Tarn ran too far with the concept, abandoning conventions like dungeon diving to recover an artifact or kill a monster, a single character directly controlled, etc. The problem with these kinds of objections, to my mind, is that Dwarf Fortress shows clearly that single character control and dungeon diving isn't what makes (some) roguelikes good (and it's obvious it isn't what makes them distinctive). So I'll agree that it may not be a roguelike by some reckoning, but it's a view of what a roguelike could be. You know, I'm no big fan of ESR, but he said something to the effect that the strength of roguelikes is that the lack of graphics allows one to pour more into the underlying game logic and create more depth than is possible when you need an animation for every possible action, etc. I think he's onto something there (something completely lost in the 7DRL concept) and Dwarf Fortress shows that in the way nethack always has, but in a new, radical way. So I would tend to look at Dwarf Fortress as a direction for roguelikes to head in, even if some would deny it a place in the genre.