Gotham
ECIP-1017 monetary policy — established the 210.7 million ETC supply cap with era-based emission reduction.
Gotham (ECIP-1017) Network Upgrade
Activation Block: 5,000,000
Activation Date: December 11, 2017
ECIP Status: Final
Overview
Gotham was the most consequential economic upgrade in Ethereum Classic's history. It established a fixed monetary policy with a hard supply cap — something the original Ethereum protocol never defined. ECIP-1017 introduced era-based emission reduction (20% every 5 million blocks), capping the total supply at approximately 210.7 million ETC. ECIP-1039 specified the precise rounding behavior for sub-wei calculations across eras.
Included Changes
| ECIP | Title | Summary |
|---|---|---|
| ECIP-1017 | Monetary Policy and Final Modification to the Ethereum Classic Emission Schedule | Era-based 20% reduction every 5M blocks, ~210.7M supply cap |
| ECIP-1039 | Monetary Policy Rounding Specification | Defines precise rounding behavior for sub-wei reward calculations |
Technical Details
- Era-based emission schedule — Block rewards reduce by 20% every 5,000,000 blocks (an "era"):
- Era 1 (blocks 1–5,000,000): 5 ETC per block
- Era 2 (blocks 5,000,001–10,000,000): 4 ETC per block
- Era 3 (blocks 10,000,001–15,000,000): 3.2 ETC per block
- Each subsequent era: previous reward × 0.8
- Supply cap — The geometric series converges to approximately 210,700,000 ETC total supply. Unlike Bitcoin's halving (50% reduction), ETC uses a smoother 20% reduction curve
- Uncle and nephew rewards — Uncle block rewards and nephew inclusion rewards also reduce proportionally with each era, maintaining consistent incentive structures
- ECIP-1039: Rounding specification — As era rewards decrease, the per-block reward eventually involves fractional wei values. ECIP-1039 specifies that rewards are rounded down (truncated) to the nearest wei, ensuring deterministic calculation across all client implementations
Context
Before Gotham, ETC had no defined monetary policy — block rewards would have continued at 5 ETC per block indefinitely, resulting in unlimited supply. The fixed emission schedule gave ETC a clear economic identity: a sound money asset with predictable, declining issuance and a known supply cap. The 20% reduction per era (versus Bitcoin's 50% halving) produces a gentler emission curve that avoids the abrupt supply shocks associated with halvings.
Outcome
Activated at block 5,000,000 on December 11, 2017. Era 2 began immediately, reducing the block reward from 5 ETC to 4 ETC. The monetary policy has operated continuously since activation, with the network currently in Era 4 (2.56 ETC per block).