Riot's overview calls Piltover "Valoran's cultural center, where art, craftsmanship, trade and innovation walk hand in hand", and gives the reason for its power in one clause: it "comes not through military might, but the engines of commerce and forward thinking". Then Arcane spent eighteen episodes showing what that sentence costs the city beneath it.
This is the hub for Piltover: what it is, who runs it, what hextech did to it, what Arcane made canon, and what the city would be in the Riot MMO. The game parts are speculation and labelled. The rest is Riot's.
What Piltover is
A port city at the southern tip of Valoran, on the cliffs above Zaun and the strait that faces Shurima. Riot describes fleets passing through its "titanic sea-gates" from all over the world, and the wealth that produces as the cause of "an unprecedented boom" in the city's growth. It is the only region in Runeterra whose power is money, and the only one that Riot describes as "reinventing itself".
Below it, in the canyons the city was built over, is Zaun. The two were one city once. They are now, in Riot's phrase, "separate, yet symbiotic societies", and the relationship between the two is the whole of Arcane and most of Piltover's politics. Zaun has a hub of its own in this series.
Who runs it
The clans. Piltover is governed by a council of its great houses, the families whose workshops and trading companies made the city: Kiramman, Caitlyn's family, whose seat on the council and whose daughter's badge tie the law to the aristocracy; Ferros, Camille's, which guards its interests with a woman who had her legs replaced with blades; Talis, which Jayce made great with hextech; and, from Noxus, Medarda, whose Mel sat on the council in Arcane and whose mother is in Noxus. The Wardens keep the peace, which in Piltover means keeping it for the clans.
What hextech did
Hextech is magic made into a machine: crystals that hold arcane power, and devices that put it to work without a mage. Jayce and Viktor built it in Arcane, and the Hexgates, portals that moved Piltover's trade across the world in an instant, made the city rich on a scale it had not been before. The technology is the region's great invention and its great danger, and the series is the story of both.
For a game, hextech is a crafting system that needs no inventing, a point made in Riot MMO classes, where a hextech marksman is the first class on our speculative list.
What Arcane fixed
Since 13 October 2023, Arcane is canon, and Piltover is the region it fixes most. The look of the city, the Academy, the council chamber, the bridge to Zaun, the faces of Caitlyn, Vi, Jayce, Viktor, Heimerdinger and Mel: all of it is now what the Riot MMO has to show, and the ending of the second season is where the city's story now stands. Any game set in Piltover is set in Arcane's Piltover, and the era question in when is the Riot MMO set? is, for this region, the question of how long after the series.
Who lives there
Riot's roster, eight strong: Caitlyn, Camille, Ezreal, Heimerdinger, Jayce, Orianna, Seraphine and Vi.
The law: Caitlyn, sheriff, and Vi, her enforcer, who came up from Zaun. The clans: Camille of Ferros, and Jayce of Talis, the Defender of Tomorrow. The Academy: Heimerdinger, a Yordle professor who has taught the city's inventors for longer than any of them have lived. The oddities: Orianna, a clockwork girl her father built to replace his daughter; Ezreal, an explorer who left the city with a gauntlet he found in Shurima; Seraphine, a singer whose gift crosses the line between the two cities.
Eight is a small roster for the region the largest audience knows best. Zaun's fourteen make up the difference, and most of Arcane's cast lives on that side of the line.
The places
The sea-gates, the Academy, the council chamber, the Hexgates. Legends of Runeterra painted Piltover and Zaun as one region with 222 illustrations, and its landmark cards, the University of Piltover, the Hexcore Foundry, the Forge of Tomorrow, are the best pictures of the upper city outside the series itself.
Piltover in the MMO, as a guess
A reading, not a report. Riot has confirmed the setting and nothing about which regions ship, or how.
Piltover is the region the Arcane audience will expect on day one, and we argue in starting zones that the twin city is the game's fourth beginning, separate from the three western regions that connect by land. Beyond that it is the setting's obvious capital: a port with sea-gates to every region, a market, an academy, a council, and the kind of vertical geography, cliffs above and canyons below, that an MMO's social hub is built for. If the Riot MMO has one city where players gather between adventures, this is the candidate.
Its story is intrigue rather than war, which makes it the counterweight to Noxus and Demacia. A player who wants to fight goes north. A player who wants to scheme, trade, invent or investigate stays here, and the council of clans supplies the factions.
What we do not know
Whether Piltover and Zaun are one zone or two.
Whether the Hexgates are a fast-travel system, which would be the most natural thing in the world and the most contested, given what the series did with them.
Whether Riot's next animated projects move the city's story before the game arrives.
For Piltover among the other twelve regions, with the numbers, see the 13 regions of Runeterra.