Core Keeper 1.3 explained: Riders of the Underground mounts, Moss biome, Scepters

Pugstorm and Fireshine Games shipped Core Keeper 1.3.0.1 — Riders of the Underground as a free major content update on 21 September 2026, framing it as the first stop on the studio’s Road to the Maw roadmap. Softcap’s explainer sticks to Pugstorm’s Confirmed Steam primaries: the 1.3.0.1 Major Update changelog, the LIVE feature write-up, the same-day Games Press release, and the follow-up 1.3.0.2 Hotfix (drill/circuitry fix).

Primary spine: Saddle mounts plus Hookshots, the Moss sub-biome and Orex cattle, a Summoning pass that makes minions permanent, and a Warlock Scepter weapon lane — with a long balance / QoL / modding sheet Softcap is treating as Confirmed end-to-end. Softcap is not inventing concurrent-player counts or “best mount” tiers beyond those published lines.

At a glance

Beat	Published detail
Version	1.3.0.1 — Riders of the Underground (free)
Live date	21 September 2026 — PC + Switch / Switch 2 / PS4 / PS5 / Xbox
Roadmap	First stop on Road to the Maw (Trials of the Depths / Beyond the Breach later)
Exploration	Saddle / Racing Saddle mounts · Hookshot / Gilded Hookshot
Biome	Moss sub-biome in Forgotten Ruins · Orex cattle
Summoning	Minions persist indefinitely · max-spawn action · spawn CD removed
Combat	7 Scepters (incl. Legendary) · Corrosion / Blizzard Staff · Sniper Rifle · Wingling / Searpent
Pets	Hoppet · Azeos Jr. · desert surprise pet
Follow-up	1.3.0.2 hotfix — drills no longer damage on first powered tick

Games Press also clocks Core Keeper past 6 million players worldwide in the pre-launch Mount Up release Softcap is citing as Confirmed press math, not a Softcap estimate.

Mounts and Hookshots

The LIVE Steam post’s Confirmed pitch: exploration already covered walking, minecarts, boats, go-karts, and teleports — 1.3 adds riding and grappling.

Saddle / Racing Saddle: place on any cattle to turn it into a mount. New Saddle UI covers naming and off-saddle behaviour (stay / roam / follow). Remove the saddle to return the animal to cattle status.

Hookshot / Gilded Hookshot: new off-hand type. Latch onto solid surfaces (walls) and pull across pits and water — Softcap is not inventing range tables beyond “grappling hook” wording in the Confirmed notes.

Go-kart handling also moves: handbrake (speed down, inertia up), increased turning, reduced inertia, plus new vehicle turn/brake key binds. Boats, minecarts, and go-karts no longer transfer to the grave on death — if you die seated, the vehicle drops into inventory instead.

Moss sub-biome and Orex

Moss sits inside the Forgotten Ruins — dark, humid, lush. Home cattle is the Orex: raptor look, docile diet of insects and Moorshrooms. Softcap is treating that temperament line as Confirmed flavour from the LIVE post, not a combat spreadsheet.

Summoning and Warlock kit

Summoning is one of the largest systems shifts on the 1.3.0.1 sheet:

• Minions persist indefinitely instead of expiring
• Two new Summoning talents replace two previous ones to match that behaviour
• Players can despawn minions manually
• New action: spawn the max available minions at once
• Minion spawn cooldown removed
• Minion base damage rebalanced against new Scepter minion-damage bonuses

Scepters are a new Warlock weapon type — seven including a Legendary. Other Confirmed weapon adds: Corrosion Staff, Blizzard Staff, Sniper Rifle. New enemies: Wingling, Searpent. Craftable Training Dummy lands for practice.

Pets, armor, Titan chests

Confirmed collectables Softcap is flagging:

Lane	Published detail
Pets	Hoppet · Azeos Jr. · “something lazy” in the Desert of Beginnings
Armor / accessories	10 armor · 15 rings · 15 necklaces
Boss loot chests	New chests for Azeos, Omoroth, Ra-Akar
Achievements	4 new

Arcane Symbiote and Electro-Pet also gain hatch colour variants in the Graphics block.

Balance Softcap is flagging

The Confirmed balance pass is dense. Softcap’s reader-facing cuts:

• Skill XP: Melee / Ranged / Magic gains now scale with attack speed; total XP to max those trees reduced (faster early points)
• Magic: Barrier gear scaling ~2× at full upgrade; mana regen no longer hard-stops after cast (continues at 50% while attacking and for 1s after); Magic tree rearranged; “Firmly grounded” removed (baseline barrier regen delay −25%); new Mental Defense talent; several mana talents reworked
• Ranged: “Weakness detection” crit chance cut to 50%
• Economy / traverse: cheaper boats, go-karts, Portals, Railway Forge; Rails craft yield 5 → 10; faster higher-tier ore smelt; fewer plants for early Gardening XP; more Tin Ore in Clay Caves
• Bosses: higher gear drop rates across a long Titan / Mass / Commander list; Titan resummon CDs “significantly” reduced
• Encounters: Spearman / Skirmisher Cavelings easier; Sunken Sea Tentacle count and damage down

Softcap is not reprinting every named armor retune (Moldweb, Slime, Scholar, Assassin, Gemstone, Sulfossil, etc.) — those sit as Confirmed “stats adjusted” lines in the Steam sheet.

QoL, modding, 1.3.0.2

Confirmed quality-of-life Softcap is calling out for daily digs: gear compare, cursor/crosshair customization, loadout cycle bind, paint brush area up to 5×5, faster Waypoints/Portals, reconnect restores client-last health, line-of-sight checks for cattle/minecarts/boats/chairs, and a real mods menu (load state, order, install source).

ModSDK: custom scene creation after full asset import; most game objects moddable; map markers via MapMarkerIconDataBlock.

1.3.0.2 Hotfix (Confirmed): drills no longer deal damage on the first game tick after receiving power — Softcap’s read: that broke circuitry builds that used drills for item sorting.

What Softcap is watching

1.3 is a traversal-and-systems drop more than a single boss chapter. Mounts + Hookshots change how Forgotten Ruins and Moss get crossed; permanent minions and Scepters rewrite Summoning / Warlock loops; the Titan chest and drop-rate pass softens farm friction on the Road to the Maw.

Primaries: 1.3.0.1 Steam changelog · LIVE feature post · 1.3.0.2 Hotfix.