What is Layer 1+?

An L1+ is a rollup that does not introduce new points of centralization or trust on top of those already present on the L1.

The term "L1+" is introduced by Facet as a way of distinguishing Facet's approach from other L2 rollups. Unlike L2 rollups, which may sacrifice some properties of the L1 to gain other features, an L1+ is designed to scale the L1 without compromise.

In Ethereum's case, many L2s have emerged, successfully preserving properties of Ethereum, including security (via data availability), programmability, transparency, and interoperability. But today's L2 offerings fall short of fully inheriting three of Ethereum's core properties:

✅ Liveness

The network remains operational and continues to process transactions, even under adverse conditions.

✅ Censorship Resistance

No single entity or group can control or censor transactions, maintaining open and unrestricted access for all participants.

✅ Credible Neutrality

The network does not discriminate for or against any specific people or any specific outcomes. All participants play by the same rules.

Let's explore each below to justify the new L1+ terminology:

Liveness

• Facet (L1+)

  • Does not introduce centralized dependencies (e.g. sequencers)—the only way to guarantee same liveness as Ethereum.

  • Fully operational as long as Ethereum is live.

• Conventional L2

  • Introduces centralized dependencies (e.g. sequencers) that can experience technical failures or outages, leading to periods of downtime where L2 cannot process transactions.

  • Requires escape hatches with timeout periods for settlement.

  • Traditional "based" sequencing can still fail if sequencing a given block isn't profitable.

Censorship Resistance

• Facet (L1+)

  • No single entity or group can censor transactions.

• Conventional L2

  • Privileged components, even if well-intentioned, can pose risk of censorship.

Credible Neutrality

• Facet (L1+)

  • All transactions processed in a transparent way without bias or favoritism.

  • No value (e.g. sequencing revenue) extracted by the protocol (think public good).

• Conventional L2

  • Privileged components introduce potential for bias in transaction reordering.

  • Revenue models extract revenue at the protocol layer, benefiting privileged parties.

Facet’s unique ability to deliver on these core Ethereum properties is made possible by a hybrid rollup construction, the Based Sovereign Rollup, which we'll explore next.