Champion backstory

Zac

the Secret Weapon

Read the backstory Abilities and gameplay guide

3Story chapters

1Story connections

2Named place connections

The person behind the champion

A story to start with

Zac is the product of a toxic spill that ran through a chemtech seam and pooled in an isolated cavern deep in Zaun's Sump. Despite such humble origins, Zac has grown from primordial ooze into a thinking being who dwells in the city's pipes, occasionally emerging to help those who cannot help themselves or to rebuild the broken infrastructure of Zaun.

Short biography by Riot Games · Data Dragon 16.20.1

What shapes their story?

The people who cared for Zac give an unlikely life a moral education as well as a home. His protection of Zaun grows from that relationship, making a product of dangerous waste capable of answering the city's hazards with compassion.

Reading note by VRC.LOL

Read Riot's full biography ↗

Follow the story

Story timeline

Follow the main developments in order, then explore their consequences. Use each chapter's links to explore the people, regions and places involved. Artwork shows the character or wider world, not an exact reconstruction of each event; calendar dates are not assigned here.

Riot Games · Regional world artwork
Awareness gathers beneath the Sump
Zac began as an unexpected result of Zaun's chemical waste, gathering in a cavern beneath the Sump. Something that might have been only another industrial hazard developed awareness and a capacity to care.
Zaun
Riot Games · Regional world artwork
An unusual body chooses a protective purpose
Choosing to help gives that unusual origin a different meaning. Moving through pipes and repairing damaged infrastructure lets him protect people in spaces more celebrated champions might never see.
Zaun
Riot Games · World artwork
The city's discarded matter chooses to help
Care from the people who recognised Zac's awareness gives his unusual origin a different future. His later protection of Zaun continues that kindness through an adaptable body. The Sump's danger explains where he came from, but does not decide what a being made there must become.
Sump Zaun

Story guide by VRC.LOL, based on the linked Riot stories. Older biographies and newer stories can differ; no exact date or current whereabouts is implied unless stated.

Picture the setting

A world behind the story

Official Riot setting artwork, not illustrations of these exact events. Open an image to see the complete composition.

**Lights and Shadows**Riot Games · World artwork

**Public Hexdraulic Descender**Riot Games · World artwork

Explore the wider region

People who shape the story

Relationships and allegiances

Discover the companions, communities and powers that matter to this champion. Each card explains the connection, rather than treating every nearby character as a friend.

Not everyone important to this story is a playable champion. The reading suggestions below are labelled separately from these story connections.

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Known places and connections

Origins, journeys and documented events. A connection here does not mean this champion lives there now.

Regional connection

Zaun

Explore the regional timeline

More about the region

A city of industry and invention beneath Piltover, where hazardous experimentation and pollution coexist with resilient communities. Its stories ask who benefits from progress and who pays for it.

Industrial cityscape

Zaun undercity

Connected levels of workshops, industry and densely inhabited streets form Piltover's counterpart. Champion stories show different lives here, from community protection to dangerous chemical experiments.

Explore this place

Lower city

Sump

Zaun's deepest inhabited level is associated with its harshest industrial conditions. Riot's gallery contrasts life here with the markets and institutions higher in the city.

Explore this place

Another perspective

Stories to read next

Continue with related characters, regional stories and other perspectives on the same themes.

Blitzcrank

the Great Steam Golem

Read backstory

Zeri

The Spark of Zaun

Read backstory

The character, in detail

Champion artwork

Explore the wider settingZaun

The story beneath the scenery

What makes this place matter?

Zaun is a lived-in home as well as an industrial undercity. Its different levels separate workshops, markets and dangerous depths. Ekko and Zeri's community ties offer a different view from the chem-barons and experiments that dominate many outsiders' impressions.

Look closer

A window into this world

Official Riot artwork. The gallery includes the regional setting; not every image depicts this exact landmark. Open an image to see the full composition.

**Sump Level**Riot Games · Runeterra world map

**Promenade Level**Riot Games · Runeterra world map

**Life Survives in the Depth**Riot Games · Runeterra world map

Sources and story contextOfficial stories, artwork credits and reading notes

Where the stories come from

VRC.LOL writes the introductions, reading notes and connections using linked Riot Universe biographies and regional guides. Short champion summaries use Data Dragon version 16.20.1. Longer histories link to the official story used; some champions currently have a shorter official overview.

What the pictures show

Artwork belongs to Riot Games. Scenery comes from Riot's Runeterra world map; champion art depicts the character. A regional illustration sets the scene when a landmark has no dedicated image. It does not show a confirmed event at that exact place.

A world still being written

Older biographies and newer adaptations can differ. These guides introduce connections rather than declaring a final chronology or a character's current whereabouts. Translations help you explore and may keep original proper names. Follow the official sources for full context.