# validator_emission (/docs/hyperparameters/validator-emission)

Slot 3 of the [emission weight vector](/docs/concepts/emission-weights):
the fraction of each block's `alpha_out` that becomes validator dividends.
Root TAO stakers are paid out of this slot via the subnet's consensus-side
root proportion. Stored as `u64` parts of `u64::MAX`.

## How it works [#how-it-works]

Per block, `alpha_out × validator_emission` goes to the validator bucket;
the root proportion of it is set aside for root TAO stakers and the rest is
distributed through Yuma Consensus dividends at the epoch.

Every set of the vector makes the chain re-solve the subnet's
[effective TAO weight](/docs/concepts/emission-weights#the-effective-tao-weight)
once, at that block, so root TAO stakers earn their **baseline** share of the
subnet's emission: what they would earn with the default validator share
(0.41 on mainnet) and the global `TaoWeight`. A slot below the default
raises the weight, a slot above it lowers the weight, and exactly the
default clears it so the subnet follows the global knob; the weight is then
left alone until the next set. The baseline never depends on the previous
vector, so changing the slot in steps cannot move root's share.

## Bounds [#bounds]

`validator_emission ≤ 0.50`, and the new value must leave room to reach
root's baseline with a TAO weight no greater than one. Writing `r` for that
baseline share, `A` for the subnet's alpha issuance and `T` for root TAO, the
floor at this block is `r × (1 + A / T)`; on a mainnet subnet with 5.4M TAO
on root, 6.5M alpha issued and `TaoWeight = 0.18` that is about 11.8%. The
floor moves with root stake, issuance and the global weight, so
`btcli subnets emission show` prints the current value. Errors: `ValidatorEmissionAboveMaximum`,
`ValidatorEmissionTooLowToPreserveRoot`, `EmissionWeightsDoNotSumToOne`.

## Reading and setting [#reading-and-setting]

```bash
btcli subnets emission show --netuid 12          # prints the current floor
btcli subnets emission decrease --netuid 12 --slot validator --by 0.05
```

Settable by the subnet owner (once per week per subnet) or root through
[`set-subnet-emission-weights`](/docs/tx/set-subnet-emission-weights); not
available on the root subnet.

## Related [#related]

* [`owner_emission`](/docs/hyperparameters/owner-emission),
  [`miner_emission`](/docs/hyperparameters/miner-emission)
* [Emission weights](/docs/concepts/emission-weights)