Reduction in refunds

The five-minute read

One action, walked through

1. Open EIP 3529 and read the status line before the examples.
2. Write down the rule in one sentence. A fair version of that sentence is: Remove gas refunds for SELFDESTRUCT, and reduce gas refunds for SSTORE to a lower level where the refunds are still substantial, but they are no longer high enough for current "exploits" of the refund mechanism to be viable.
3. Name the object that changes: SELFDESTRUCT, SSTORE, FORK_BLOCK.
4. Ask what an old client, an old contract, or an offline counterparty does. If the document is silent, the silence is part of the design.

The argument, unpacked

What has to be true

• You are implementing EIP 3529 at the status the text itself states: Final.
• The object that has to change is SELFDESTRUCT, SSTORE, FORK_BLOCK. A neighbouring document with a similar name is not this one.
• Constants in the text can be superseded by a later fork. Cite the EIP number and the fork you mean.

What happened after the paper

The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it. Later documents can narrow, replace, or ignore this one. Cite the number you mean.

What to check before you use the idea

• What does Reduction in refunds charge, reject, or redefine on the first touch versus a later one?
• Does a reverted subcall roll the change back?
• Can you point at the object in a client: SELFDESTRUCT, SSTORE, FORK_BLOCK?

Terms

EIP 3529

The public text titled Reduction in refunds.

Final

The document's own label for how finished the text is. It is not a market fact.

The problem the paper names

An underpriced or ambiguous EVM rule is not a feature. It is a block that takes longer than the gas limit claimed, or a client that disagrees about the result.

What the design proposes

• Remove gas refunds for SELFDESTRUCT, and reduce gas refunds for SSTORE to a lower level where the refunds are still substantial, but they are no longer high enough for current "exploits" of the refund mechanism to be viable.
• Gas refunds for SSTORE and SELFDESTRUCT were originally introduced to motivate application developers to write applications that practice "good state hygiene", clearing storage slots and contracts that are no longer needed.
• However, the benefits of this technique have proven to be far lower than anticipated, and gas refunds have had multiple unexpected harmful consequences: Refunds give rise to GasToken.

How the mechanism is specified

• Taken from the specification, the next constraint is: Gas refunds for SSTORE and SELFDESTRUCT were originally introduced to motivate application developers to write applications that practice "good state hygiene", clearing storage slots and contracts that are no longer needed.
• Locate SELFDESTRUCT, SSTORE, FORK_BLOCK in EIP 3529 and apply it to one transaction or call.
• Then check the failure the class of rule always has: a node that did not upgrade, a reverted call, a replayed signature, or a peer that does not speak the message.

What this page does not treat as proven

• A gas or opcode change is not a throughput benchmark. It is a relative price and a validity rule.
• Constants in the text can be superseded by a later fork. Cite the EIP number and the fork you mean.
• The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it.

Why a venture studio still reads it

Use EIP 3529 when a pitch says 'Reduction in refunds' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.