Hearthstone's Reign of the Black Empire Arrives October 20 — Monk Class Follows in March 2027

Blizzard’s BlizzCon 2026 Hearthstone reveal covers three separate timelines, and it’s worth keeping them straight: one expansion landing in five weeks, a Battlegrounds update landing even sooner, and a genuinely rare new class that’s still six months out. Here’s what launches when, and what each piece actually changes.

The Timeline

Date	What Arrives
September 22, 2026	Battlegrounds Aberrations minion type
October 20, 2026	Reign of the Black Empire expansion, Assemble keyword, overhauled Journal (“The Journey”)
March 2027	Monk class — Hearthstone’s first new class in six years

Reign of the Black Empire: Old Gods at Their Peak

Confirmed for October 20, 2026, Reign of the Black Empire sends Hearthstone back to ancient Azeroth “when the Old Gods were at the height of their power” — the era the expansion’s title refers to, predating the current Warcraft timeline by tens of thousands of years. Blizzard’s own materials point to Yogg-Saron, C’Thun, and N’Zoth as figures from this period, framed against the Titans who eventually curbed the Old Gods’ rule.

Assemble: A New Keyword Built Around Combination

Assemble is the expansion’s headline mechanic: it merges two cards together into a single new card that blends their effects, rather than simply adding a bigger stat-line minion. Blizzard has described the results as opening the door to “wildly unpredictable combinations,” and multiple outlets covering the reveal cite a curated pool of roughly 250 cards eligible for Assemble combinations specifically — a limit apparently designed to keep the mechanic from generating unbounded, unbalanced results. Exact combination rules and the full card pool haven’t been published in detail yet.

The Journal Overhaul, aka “The Journey”

Alongside the expansion, Blizzard is overhauling Hearthstone’s Journal system — coverage of the reveal refers to the updated feature as “The Journey” — which ties each expansion’s quests, achievements, and events together with a connected narrative thread rather than leaving them scattered across separate menus. Blizzard describes it as something that will “continue to grow alongside us as our journey continues, connecting dots from the past through the present and beyond.” It’s arriving free for all players alongside the October 20 expansion, not gated behind a purchase.

Battlegrounds Gets Aberrations First — September 22

Before the expansion even lands, Battlegrounds gets its own new content: Aberrations, a minion type Blizzard describes as “born from the corruption, experimentation, and influence of the Old Gods,” arriving September 22, 2026. Coverage of the reveal indicates Aberrations tie into a broader Old God awakening mechanic in Battlegrounds specifically, though Blizzard’s own confirmed wording is limited to the minion type and its thematic framing rather than a full mechanical breakdown.

The Monk: A Genuinely Rare Addition

Hearthstone hasn’t added a new playable class since Demon Hunter in 2020, making the Monk’s confirmation a bigger structural deal than a normal expansion class. Blizzard’s own language calls it “the game’s first new playable class in six years,” arriving in March 2027. The reveal cinematic centers on Chen Stormstout, the Pandaren brewmaster from Warcraft lore, though Blizzard hasn’t confirmed him as the class’s default hero, nor published any Monk cards, a Hero Power, launch archetype, card count, or how the class will interact with Standard rotation. Coverage describes the class only in broad thematic terms — “signature fluid playstyle and adaptable nature” — pulled directly from Blizzard’s own framing, not specific mechanics.

Class Chronology, For Context

Demon Hunter, added with Ashes of Outland in April 2020, was Hearthstone’s last new class before this announcement — making Monk’s March 2027 arrival roughly seven years later, consistent with Blizzard’s own “six years” framing measured from Demon Hunter’s reveal rather than its exact release date. Some outlets covering the same announcement described it as “four years” instead; that figure doesn’t match Blizzard’s own stated wording, so this piece uses Blizzard’s own framing rather than the inconsistent secondary figure.

What’s Still Unconfirmed

Blizzard has not published preorder bundle names or pricing for Reign of the Black Empire, the expansion’s total card count, exact Assemble combination rules beyond the curated-pool figure reported by outlets at the reveal, or any Monk-specific mechanics, Hero Power, or cards. Treat anything beyond what’s listed above — including specific card previews or datamined leaks that may circulate before October 20 — as unconfirmed until Blizzard publishes it directly.

Bottom Line

Three separate dates, three separate scopes: Aberrations hits Battlegrounds September 22, Reign of the Black Empire and its Assemble keyword (plus the free Journal/Journey overhaul) launch October 20, and the Monk — a genuinely uncommon new-class addition — doesn’t arrive until March 2027. The expansion and Battlegrounds update are the near-term news; the Monk is the long-lead story worth tracking as more details emerge.

For more from BlizzCon 2026, see our World of Warcraft: Forever guide and our Heroes of the Storm Xal’atath coverage, or visit our Gaming hub.