Polkadot Slashing Explained
How Slashing Works on Polkadot
Polkadot enforces economic penalties to deter two classes of validator misbehaviour:
| Offence Type | What triggers it | Typical Slash Size | Notes |
|---|---|---|---|
| Unresponsiveness (offline) | Validator misses > 10 % of its assigned blocks during a session | ≈ 0.1 % of the stake tied to that validator | Considered a minor offence. The validator is also chilled (kicked out) for at least one era. |
| Equivocation (double-signing) | Validator signs two different blocks for the same slot (BABE) or two conflicting votes (GRANDPA) | From 0.01 % up to 100 % depending on how many validators equivocated in the same slot | A major offence. Penalty scales quadratically with the fraction of validators involved |
Slash-size formula (equivocation)
slash = min((3 × x / n)^2, 1)
x= number of misbehaving validatorsn= total validators in the active set
Examples:
- 1 / 100 equivocators →
min((3 × 1 / 100)², 1)≈ 0.09 % slash - 20 / 100 equivocators →
min((3 × 20 / 100)², 1)= 36 % slash
Who Pays the Penalty?
- The validator’s self-bond and each nominator’s bonded DOT are slashed pro-rata.
- Only the stake exposed to that validator is affected. Nominating 16 different validators isolates risk to ¹⁄₁₆ of your bond per incident.
What Happens to Slashed Funds?
- Slashed DOT is immediately removed and frozen for 256 eras (~9 months).
- After that period: 50 % is burned and 50 % goes to the Treasury.
Chilling & Re-Entry
- A slashed validator is chilled (removed) and must wait at least one era before re-entering.
- Nominators are automatically re-nominated to the validator’s stash. For uninterrupted rewards, manually switch to a trusted validator.
Mitigating Your Risk
- Distributing your stake across multiple pools
| Action | Benefit |
|---|---|
| Split nominations | You can distribute up to 16 nominations from one account, isolating slash exposure. |
Key takeaway:
Slashing is rare and manageable. Choosing reputable validators like Pier Two—with proven uptime, high self-stake, and robust fail-over—greatly mitigates the risk.
Updated about 1 month ago