Interesting discussion above! For one, I wasn't aware of what Civac says above, that the game will effectively create money to maintain unsustainable trade deals vis a vis the AI, but only for them. On the other hand, though, I guess by the same token, it also arbitrarily takes money away from
everyone over time throughout the game via the inflation mechanic, which I am pretty sure Civ 3 lacks completely. I haven't played Civ 3 seriously as an adult, however, so I could be mistaken, but I believe this was a concept introduced in the subsequent title.
I'm pretty 50:50 when it comes to Civ3 and Civ4, and I think part of the reason Civ3 appeals to me is the nostalgia factor - it was my first Civ game, buying it in 2003, and even after I bought Civ4 in 2005, it ran rather poorly on my computer at the time, so I went back to Civ3 and didn't really return to 4 in a serious manner until 2010 - by which point I was an established member of the Civ3 community here, and thus well-versed in what Civ3 had to offer veterans of the game. In the 2010s, I probably played 60% Civ3, 40% Civ4, but also spend a good amount of time creating a scenario editor for Civ3, one of my primary side projects.
While I was only a kid too young to properly appreciate the depths of a well-made strategy game at the time, I still extensively played Civ 3 in the early 2000s, so that nostalgia factor is certainly there for me too, and I know what you mean. At the same time, I would say that Civ 4 still holds more nostalgic appeal for me, since I ended up playing it even more and over a longer span of time, during which I became old enough to play Civ seriously and started to gain familiarity with a lot of the "orthodox" gambits of play in its community, similarly to what you said yourself with respect to the third game.
So, at the end of the day, it seems that this ends up being the dominant factor for most people (and not even wrongly, per se!). When this question gets asked of veteran Civ 3 players, the answer tends to be something fairly close to "It's a great game that I enjoy the look of, know well, and I don't really feel like deviating" and not some highlighting factor of how Civ 4 is
strategically inferior in any definite way, other than the argument that "simplicity is golden, and 4 got
too complex" which I hear from time to time, very unlike the criticisms of 5 (and maybe 6, though I honestly never even bothered looking into it much, but did play and follow along with 5 for a few years when it was new).
What is the appeal of III vis-a-vis IV? I think there are two primary arguable points:
- Some find that it offers just the right balance of streamlined, fast-paced gameplay and strategic depth. IV is deeper and more flexible. But III is very low-friction. No deciding which promotion to give a unit, for example, it just becomes Veteran or Elite. Eight governments rather than 25 civics. Plus keyboard shortcuts to make it really quick to take actions. The series has generally added more complexity over time, and sometimes I'm in the mood for a game where I can just focus on the higher level.
To me, this is actually a very interesting point; because, not only does it open a valid question within the Civ series itself, but broaches perhaps
the leading one between Civilization as a franchise and other, more "serious" and simulative historical strategy titles, which sometimes offer more realism and granularity which end up coming at the expense of fun. In my opinion, that is a glory of Civilization, that it
feels like you're
really fighting a certain war or leading a certain culture at a certain point in history, allowing your imagination plausible free reign of roleplay in the midst of gameplay mechanic dilemmas which themselves require plenty of concerted thought and forward thinking, which together creates a really rich and immersive experience. The beauty of it is that it doesn't even require getting bogged down in the cryptic complexities of certain actual realities, when the essence of the thing offers the suspension of disbelief a helping hand in a simple modeling of a concept (such as, among many other similar examples along these lines in the game, irrigation for farms providing extra food when connected, without bothering with any contingent questions of the number of connecting farms drawing this, the amount of fresh water the original source is already adjacent to, etc., for instance; the concept is still there and enriches the depth and experience of how you want to develop your land without assigning you opaque homework about it first, both of which makes it more inviting to interact with).
By the same token, though I still think that Civ 4 strikes the better balance, the question of complexity is still relevant, even within the series that already is known for abstracting much of this. I once asked Civman here the same question, and he equated the additional complexity of 4 (such as specialists and great people) to adding more superficial tech trees, when the individual tech tree in the third game struck just the right balance on its own. I don't personally agree with that (and, a key difference between a game like Civ 4 in this regard and other strategy games, notably Civ 5, is that this "secondary tech tree" comes at the expense of and is interrelated to the "original" one, unlike a lot of strategy games where several branches of the same tree are mutually inclusive and don't entail meaningful opportunity costs), but it still represents an interesting contention in what should be the right degree of complexity, even within a game such as Civilization, which candidly is not a simulation, but rather a deep strategy game with either a fun coat of historical paint or something aiming to look and feel like actual history without aiming to actually simulate it.
- The scenario library. Civ3 is more easily moddable by non-programmers. So there are a lot of historically-inspired scenarios, some authored by actual historians. I'd love to see Firaxis return to a "moddable by laypeople" approach with VII.
While the boxed game of Civ 3 came with so many fun user-made scenarios, this is an interesting point in my opinion, since (as far as I know, and again I could be wrong) Civ 3 does not come with the "World Builder" that 4 does, at least not out of the box. If you just mean scenario creation, I think Civ 4 is much more inviting towards this end, between the two.
A lot of Civ 4 stuff is in XML, too, which doesn't take any special programming knowledge to modify. I can't speak for a comparison to Civ 3 in this regard, though.
There are some more niche reasons as well. Civ3 handles larger maps better without the risk of memory allocation failures (if only IV had had a 64-bit version...). There are a handful of people (you know who you are if you're reading this) who really don't like IV's graphics. The "suicide catapult" mechanics in vanilla IV turned a number of people away, and some missed the more flexible Civ3 bombardment options. In III, you can turn an enemy's land into a moonscape of craters, like the Western Front in the Great War, if you have sufficient advantages in the air or with artillery, whereas bombardment is basically limited to city defenses and strafing units in IV.
This aspect I completely agree with, actually. However, I have switched over to the excellent Realism Invictus mod years ago, which actually completely remodeled this (as you are likely already aware) and it ended up looking a lot more like Civ 3 in this regard. As a criticism of the base game, I'd completely agree with the distaste for the siege mechanic, but, I will still offer a small apology: it does represent a good gameplay counter to the longstanding disdain for the "stack of death" in that, the bigger your stack, the more vulnerable to collateral damage it becomes. Historically, that is pretty dubious, but in strict gameplay terms it did provide an interesting dynamic against sheer weight of numbers in unpunished concentration being the trump card which seems to nullify a lot of tactical play. Vanilla Civ 4 also gave cavalry a "flanking" attack which targetted siege first, which made
that a counter against the thing that counters stacks, so you get more dynamic and interesting warfare. I still of course prefer RI and its (in my opinion) several improvements (which includes ranged bombardment again for gunpowder era artillery onwards

), but for the detractors against the way this looked and felt in Civ 4, I do at least understand.
The map scaling is a valid point. I do think that Civ 4 provides a richer and more dynamic degree of depth with the same amount of "map real estate," but the fact that it is more constrained makes sense, and does still come across as less "epic" than a game that is truly massive. (Though, of course, things in Civ 3 like teleporting with railroads also kind of detracts from this, IMO.)
On the graphical side, it's more muddied for me. On the one hand, a distaste for the move towards a more cartoonish look (though, I think the latent unrealism here has more to do with 2005 than a deliberate artistic style, as the sixth titles seems to have shamelessly gone for) makes a lot of sense for me, and I like the warm color palette and "godlike" perspective of a fictional world that Civ 3 provides. There are only a couple of nitpicks with the Civ 3 map that I have, such as the cityscape graphic being replete with all kinds of what is otherwise represented by expensive buildings from the get-go, and being identical to one another (in the classical era, your settler drops down their knapsack and up comes a colonnaded temple and paved city square immediately, for instance; whereas in 4, a new city is visually small and rudimentary until its population grows, and it has no special architecture unless that gets built there), and the static icons for resources look fairly ugly (the image of a cluster of grapes covered by a mine, for instance, or the frozen green fish in the sea paralyzed above the water), and lastly that "irrigation" is strangely an improvement rather than a feature of agricultural land, such that you very strangely have ruts of water as the graphical representation rather than fields of crops.
However, while I like Civ 3 and how it looks overall, I simply can't go back to that UI without frustration. Civ 4's UI is probably one of the best of all time, in my opinion. Aesthetically, the icon art is beautiful (and, ironically, Civ 3's leaderheads and UI icons are comparatively kind of disturbing, from the Zoltar slow motion mood swings to the Vaporwave toilets of sanitation), but from a sheer usability and gameplay standpoint, for me at least, Civ 4 is almost seamlessly good, with several hotkeys, toggleable menus, and a huge density of information cleanly presented and easily sortable. A lot of that same information is shown in Civ 3, but getting to it and interacting with it is a lot more "high friction," contrary to the strategic gameplay, in my opinion.
As for the exploits? There are rules about which exploits are allowed and disallowed in the competitive (Hall of Fame and Game of the Month) arenas of Civ3. How enforceable this is, I'm not sure (I'm not on the Hall of Fame/GOTM staff), but there's a list of
disallowed exploits (although the gold-per-turn and then canceling the deal through war is allowed). But these exploits aren't necessarily the way to victory. Sure, if you are going for the quickest Conquest or Domination win, being a perfidious backstabber may be the way to go. But if you are going for a Cultural 20K or Space Race victory, let alone Diplomatic, it's probably counter-productive. I played quite a few Cultural 20K games in January in my quest to become the lowest-ranked Quartermaster in the Hall of Fame competition, and I don't think I broke a deal once. City development, expansion via settlers, and a bit of luck with scientific great leaders was much more important than securing high-level domination through treachery.
I did not know that there were player-enforced rules against certain gambits in Civ 3's Hall of Fame! That's funny, because in Civ 4's competitive community, it seems to be "even if it was an oversight by the developers and clearly an unintended loophole, the fact that Firaxis published it makes it sacred canon (no mods, you noob lol) to be wrested to maximum advantage" which might be part of the disparity here when it comes to records. I know that there are restrictions to games like no tech trading and such, but these are game options that are set from the beginning, not house rules that the player must be mindful to abide by.
So largely, yes, I'd say IV is a proper successor to III, unlike V/VI to IV. But they both have their charms. It's like how I play both Railroad Tycoon II and Railroad Tycoon III - each has its strengths, and RT III has more depth, but both are good games. Whereas I don't play Sid Meier's Railroads! - it went off the rails a bit too much and is widely regarded as not as good as its two predecessors (it also likes to crash on launch on for me, even when I do try to give it a fighting chance).
Having just played a tiny smattering of Railrood Tycoon II but knowing that it has a strong reputation (unlike the III, which, ironically again, introduced 3D graphics and stuff), what are the main talking points against it, if it's not another "I just grew up knowing RT2 and don't want to learn another game" situation?
^But Civ III is basically the same as Civ IV in regards to how commerce works. Both are slider-based games where you can redirect up to 100% of your commerce income to science, and in both cases the AI tends to direct a significant portion, but usually not all, of their gold to that purpose. I'd have to check for Civ IV, but in Civ III, the AI will trade enough gold per turn to force it to decrease its science rate if you are offering something it really wants. So if it's running a +6 surplus at 60% science and you offer it Oil that it really wants, it might offer 25 gold per turn and turn its science down to 40%. As far as I know, the same could apply in IV? Or will the AI not trade more than its current surplus, regardless of what its science slider is set to?
There is a classic Civ III strategy, most used for space race games, of trading techs to all other civs, which brings in more gold than it costs to research it, at least on larger maps if you've discovered most of the other civs. This enables increasing your own science rate to 100% if the strategy is successful enough, and reaching the Space Age super early (as in Hall of Fame games), and either gaining a tech advantage and/or selling the AI enough techs that it is giving most of its income to you. Which is not such a feasible strategy in IV, since you can only trade tech for lump sum gold. So perhaps reducing that strategy was part of the motivation as well.
This kind of a gambit I can clearly see being intentionally ruled out in Civ 4. While it's kind of cool in that it represents an international economy of technology which is a function of a limited supply of available money, the fact that you can command a higher price for the tech than its actual research cost while leaching everyone else's free commerce and preventing them from researching independently on their own is obviously extremely "gamey," because then you can just use the difference to fund an inordinate amount of standing military while still being minimally at technological parity with everyone else.
If so, did it work? If I look at the Civ III Hall of Fame for Standard size maps at the lowest difficulty, the Space Age dates are 550 AD to 1210 AD. For Civ IV, it's 280 AD to 1586 AD. To me that suggests that the top players found other ways to win extremely quickly anyway, but perhaps the nerfing of that strategy made it somewhat more difficult in general, for the average player.
Reading those AARs for those wins is actually extremely interesting. As I said, I prefer the modded the game, but the amount of calculated thought that went into optimizing a BC spaceship launch (which if I recall didn't end up making it in time, but still, even as a feat unto itself is amazing) was thrill to read, already being familiar with the constraints and obstacles of a typical game.