Each numbered Dynasty Warriors installment comes in a set of three games. This is also true of Samurai Warriors, and the collaboration games (Gundam Musō, One Piece Pirate Warriors, Hyrule Warriors, etc.) will often have a variation of it. The three versions of Dynasty Warriors are as follows:
The Base Game (e.g. Shin SangokuMusō 7/Dynasty Warriors 8)
These are the core numbered releases, and the ones that tend to see all the major changes. They will often appear at the start of a new hardware cycle to take advantage of graphical and processing enhancements made since the last main entry, will offer significant gameplay changes (while the base combat of course always remains comparable, things like modes, story progression, RPG elements and other features can and do change quite frequently and dramatically). This is when the vast majority of new characters will be introduced and existing characters will be completely redesigned from the ground up, oftentimes both aesthetically and mechanically. Some characters will lose former signature weapons and gain new ones (or in the case of Dynasty Warriors 9, get shifted into a different weapon class).
You might see new areas of China rendered and new parts of the Romance of the Three Kingdoms story included that weren't before, or parts that were previously skimmed over for time and resource constraints will now be explored in greater detail (this oftentimes goes hand-in-hand with a particular new playable character). These are the games that receive the lion's share of Koei-Tecmo's resources and publicity, building lots of pre-release marketing hype. In recent years they also tend to get supported for several months afterward with a barrage of premium downloadable content, including special pre-order exclusive costumes, new weapons, stages, music tracks, and sometimes even new entire characters.
Starting with Dynasty Warriors 3, each numbered entry has received a secondary release within 12 to 18 months of the game's original launch, subtitled Moushouden. “Moushouden” means “Mighty Legend”, and gets appropriately localized into English as “Xtreme Legends”, spelled precisely that way. The name is in reference to Lu Bu, known as one of the fiercest, most powerful and most bloodthirsty warlords in Chinese history, and it's Lu Bu who usually appears on the box art of Moushouden expansions in lieu of series mascot Zhao Yun.
Back in the olden days, Moushouden/Xtreme Legends releases were actual expansion packs: Secondary discs you would buy and that would interact with previous save data you had from the current base Dynasty Warriors game. You could also compare them to the myriad of revisions Street Fighter games tend to get over their lifespan as they bring with them gameplay tweaks and balancing, except in this case there's only one instead of ten gazillion. But Moushouden expansions also bring with them a wealth of new content, often in the form of new game modes and revisions to existing ones. There will usually be new and expanded story chapters and missions, sometimes you see a new and harder difficulty mode, and whatever the current weapon and combat system is will often get honed and refined. Some Moushouden expansions give you greater control over NPC officers in your squad. You may also see new characters, though not as many as you would in a new numbered release.
Nowadays though, Moushouden/Xtreme Legends releases are more akin to a “Definitive Edition” release, or what we old-timers used to call a “Game of the Year” edition, including the base game alongside what would have comprised the hypothetical Moushouden expansion pack. They will also include all the DLC from the base game as standard, though some of the most recent releases have tried to push it by adding a raft of new DLC just for these games. Thankfully, this is usually just nonessential cosmetic changes, like novelty costumes and skins, and can be safely ignored.
It is somewhat misleading to lump these games in with the others as they are fundamentally something different entirely. But, given the titling convention, these *are* technically the third release in a given Dynasty Warriors set, and they are in some ways the most important to address. An Empires game is not a further revision of a numbered Dynasty Warriors and its expansion: Rather, it is a completely new game built from those games' engines, mechanics and assets.
Dynasty Warriors games, indeed almost all musō games, are fiercely and proudly story-driven. Being an adaptation of a beloved novel, the Romance of the Three Kingdoms story is without question the main intended draw for Dynasty Warriors, alongside whatever other clever gameplay things the series does. Story Mode, in whatever form it takes, will comprise the overwhelming majority of your time spent with Dynasty Warriors, and any other mode is tacitly meant to be seen as a bonus. “Free Mode” simply allows you to replay a story mission with any character you want and the score attack gameplay in the various “challenge modes”, Dynasty Warriors' most overt link back to its arcade roots, will generally not keep you too busy after the fact: Omega Force really want you to experience the epic drama of Romance of the Three Kingdoms through their playground based on it. And that has to be respected, especially since even the main campaigns of these games give you so much content you can easily get 50-150 hours out of just that. And by the time you're finished, well, that's right about the time the next release will be ready for you.
Not so with the Empires games. While saying so would be unfair to the really quite profound gameplay mechanics they work with, if I may force a simplistic comparison for the point of argument...Whereas the main numbered entries and Moushouden tend to privilege their narratives, Empires leaves the storytelling up to you. Reaching back to Koei's roots as the company that made the groundbreaking Nobunaga's Ambition, the Empires releases can only be described as Grand Strategy/musō hybrids. In fact, they're *primarily* Grand Strategy games, with the musō combat being used just for the battle system.
You can choose any character in the game, even NPCs and custom characters (all Dynasty Warriors games have a robust character creation feature, and the Empires titles go out of their way to showcase this) and play through any starting scenario of your choosing. You can choose to stick close to history (or the book) or decide to go off in a completely original direction. Much of the traditional Grand Strategy gameplay is conveyed through the “Political Stage”, where matters pertaining manufacturing, diplomacy and government policy are handled with the expected detail. The “Battle Stage” is exactly what it sounds like, but decisions made during the “Political Stage” can and will affect how battles play out. The battles themselves are also more complex affairs: Rather than fulfilling a set series of objectives that progress the story, here battles require a strategic grasp of the entire playfield: Capturing bases form supply lines that determine how much territory your army controls, which affects the stats of all combatants (a very Go-inspired mechanic). Certain bases have certain added effects, like artillery fire or health restoration. Capturing the enemy HQ will always result in a victory, but a certain amount of care and nuance is required in order to do this successfully.
While the Dynasty Warriors Empires games will likely not offer the same level of detail as a Paradox Interactive title, or even a Nobunaga's Ambition or Romance of the Three Kingdoms game, they offer a very pleasing mid-point between that style of gameplay and the standard musō genre fare: A fine meeting of PC and arcade gaming sensibilities. Some Empires games, most notably Dynasty Warriors 5 Empires and Dynasty Warirors 8 Empires, also have a Free Mode markedly different from the ones in the other numbered games: An instant action mode where the player can specify the battle stage, the roster of each army, which army is invading and which is defending (indeed, this is a feature I'm a big fan of: The ability to play purely defensively, repel an invading army and take their territory for good measure. That's a path to unification I can get behind), the level of each side, who the commander is and what the stage music is. In at least Dynasty Warriors 8 Empires, each playable character's attack string is unlocked by default in Free Mode, as well as most items (which, when equipped, apply certain buffs). The rest, as well as the other levels of weapon, are easily acquired through gameplay. And the battle system is nearly identical to the way it is in the campaign.
Because of this I find the Empires games offer something noticeably lacking in every other version of the numbered releases: Replayability. The other versions (as well as the collaboration titles) have an incredible amount of content, but once you've done it all there's little reason to continue playing, unless you want to start from scratch. The story is the primary reason you play these games (though recent releases like Warriors All-Stars and, by the looks of it, Dynasty Warriors 9, have attempted some creative ways to work around this), and once you've finished it the game kind of expects you to move on. But between the innumerable combinations and permutations they allow thanks to their more explicit Grand Strategy lineage, as well as the complete customizability of Free Mode, the Empires games can stay with you as long as you want them to. I have spent the overwhelming majority of my time in Dynasty Warriors 8 Empires in Free Mode, and I've logged near 150 hours between my PC and Nintendo Switch copies.
This then is the reason I will probably hold off on Dynasty Warriors 9. Not because the game looks bad, but rather because I want to wait for Dynasty Warriors 9: Xtreme Legends and Dynasty Warriors 9 Empires to come out. Which, given tradition, should be in another year or so. I can't wait to see how this new framework for Dynasty Warriors will be built upon, and especially how the next Empires is going to translate things like the new open world mechanics. But, just because I'm planning to wait, doesn't mean you have to. But, why on Earth wouldn't you wait, given all I've just said about how the Xtreme Legends and Empires games tend to improve on the base releases? To answer that, we'll need to get under the surface a bit and look at the big secret to Dynasty Warriors' success: A secret this unusual release schedule in truth faithfully nurtures and upholds...