diff --git a/l1-contracts/src/core/libraries/Errors.sol b/l1-contracts/src/core/libraries/Errors.sol
index 8f385ff1eae4..8496265b326f 100644
--- a/l1-contracts/src/core/libraries/Errors.sol
+++ b/l1-contracts/src/core/libraries/Errors.sol
@@ -198,6 +198,7 @@ library Errors {
   error TallySlashingProposer__SlashOffsetMustBeGreaterThanZero(uint256 slashOffset);
   error TallySlashingProposer__InvalidEpochIndex(uint256 epochIndex, uint256 roundSizeInEpochs);
   error TallySlashingProposer__VoteSizeTooBig(uint256 voteSize, uint256 maxSize);
+  error TallySlashingProposer__VotesMustBeMultipleOf4(uint256 votes);
 
   // SlashPayloadLib
   error SlashPayload_ArraySizeMismatch(uint256 expected, uint256 actual);
diff --git a/l1-contracts/src/core/slashing/TallySlashingProposer.sol b/l1-contracts/src/core/slashing/TallySlashingProposer.sol
index 6f0a7d98b7bf..01e59de9a38e 100644
--- a/l1-contracts/src/core/slashing/TallySlashingProposer.sol
+++ b/l1-contracts/src/core/slashing/TallySlashingProposer.sol
@@ -355,6 +355,11 @@ contract TallySlashingProposer is EIP712 {
     // We have allocated 4 bytes32 slots = 128 bytes maximum
     uint256 voteSize = COMMITTEE_SIZE * ROUND_SIZE_IN_EPOCHS / 4;
     require(voteSize <= 128, Errors.TallySlashingProposer__VoteSizeTooBig(voteSize, 128));
+
+    require(
+      COMMITTEE_SIZE * ROUND_SIZE_IN_EPOCHS % 4 == 0,
+      Errors.TallySlashingProposer__VotesMustBeMultipleOf4(COMMITTEE_SIZE * ROUND_SIZE_IN_EPOCHS)
+    );
   }
 
   /**
diff --git a/yarn-project/aztec/src/cli/chain_l2_config.ts b/yarn-project/aztec/src/cli/chain_l2_config.ts
index bddba40c9725..aac48b15c32f 100644
--- a/yarn-project/aztec/src/cli/chain_l2_config.ts
+++ b/yarn-project/aztec/src/cli/chain_l2_config.ts
@@ -123,11 +123,7 @@ export const alphaTestnetL2ChainConfig: L2ChainConfig = {
   /** The minimum stake for a validator. */
   ejectionThreshold: DefaultL1ContractsConfig.ejectionThreshold,
   /** The slashing round size */
-  slashingRoundSize: 32 * 6, // 6 epochs
-  /** The slashing quorum */
-  slashingQuorum: (32 * 6) / 2 + 1, // 6 epochs, majority of validators
-  /** Governance proposing quorum */
-  governanceProposerQuorum: 151,
+  slashingRoundSizeInEpochs: 4,
   /** Governance proposing round size */
   governanceProposerRoundSize: 300,
   /** The mana target for the rollup */
@@ -219,9 +215,9 @@ export async function getL2ChainConfig(
   return undefined;
 }
 
-function enrichVar(envVar: EnvVar, value: string) {
+function enrichVar(envVar: EnvVar, value: string | undefined) {
   // Don't override
-  if (process.env[envVar]) {
+  if (process.env[envVar] || value === undefined) {
     return;
   }
   process.env[envVar] = value;
@@ -306,9 +302,9 @@ export async function enrichEnvironmentWithChainConfig(networkName: NetworkNames
   enrichVar('AZTEC_PROOF_SUBMISSION_EPOCHS', config.aztecProofSubmissionEpochs.toString());
   enrichVar('AZTEC_ACTIVATION_THRESHOLD', config.activationThreshold.toString());
   enrichVar('AZTEC_EJECTION_THRESHOLD', config.ejectionThreshold.toString());
-  enrichVar('AZTEC_SLASHING_QUORUM', config.slashingQuorum.toString());
-  enrichVar('AZTEC_SLASHING_ROUND_SIZE', config.slashingRoundSize.toString());
-  enrichVar('AZTEC_GOVERNANCE_PROPOSER_QUORUM', config.governanceProposerQuorum.toString());
+  enrichVar('AZTEC_SLASHING_QUORUM', config.slashingQuorum?.toString());
+  enrichVar('AZTEC_SLASHING_ROUND_SIZE_IN_EPOCHS', config.slashingRoundSizeInEpochs.toString());
+  enrichVar('AZTEC_GOVERNANCE_PROPOSER_QUORUM', config.governanceProposerQuorum?.toString());
   enrichVar('AZTEC_GOVERNANCE_PROPOSER_ROUND_SIZE', config.governanceProposerRoundSize.toString());
   enrichVar('AZTEC_MANA_TARGET', config.manaTarget.toString());
   enrichVar('AZTEC_PROVING_COST_PER_MANA', config.provingCostPerMana.toString());
diff --git a/yarn-project/aztec/src/sandbox/sandbox.ts b/yarn-project/aztec/src/sandbox/sandbox.ts
index 4ca7c04f3b96..1200c401b219 100644
--- a/yarn-project/aztec/src/sandbox/sandbox.ts
+++ b/yarn-project/aztec/src/sandbox/sandbox.ts
@@ -82,6 +82,7 @@ export async function deployContractsToL1(
       salt: opts.salt,
       feeJuicePortalInitialBalance: opts.feeJuicePortalInitialBalance,
       aztecTargetCommitteeSize: 0, // no committee in sandbox
+      slasherFlavor: 'none', // no slashing in sandbox
       realVerifier: false,
     },
   );
diff --git a/yarn-project/end-to-end/src/e2e_epochs/epochs_invalidate_block.test.ts b/yarn-project/end-to-end/src/e2e_epochs/epochs_invalidate_block.test.ts
index e829aa783c46..693dc2f7b110 100644
--- a/yarn-project/end-to-end/src/e2e_epochs/epochs_invalidate_block.test.ts
+++ b/yarn-project/end-to-end/src/e2e_epochs/epochs_invalidate_block.test.ts
@@ -52,6 +52,8 @@ describe('e2e_epochs/epochs_invalidate_block', () => {
       archiverPollingIntervalMS: 200,
       anvilAccounts: 20,
       anvilPort: ++anvilPort,
+      slashingRoundSizeInEpochs: 4,
+      slashingOffsetInRounds: 256,
       slasherFlavor: 'tally',
     });
 
diff --git a/yarn-project/end-to-end/src/e2e_p2p/add_rollup.test.ts b/yarn-project/end-to-end/src/e2e_p2p/add_rollup.test.ts
index f3cc146fea84..5a27571ae678 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/add_rollup.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/add_rollup.test.ts
@@ -75,7 +75,6 @@ describe('e2e_p2p_add_rollup', () => {
       initialConfig: {
         ...SHORTENED_BLOCK_TIME_CONFIG_NO_PRUNES,
         listenAddress: '127.0.0.1',
-        governanceProposerQuorum: 6,
         governanceProposerRoundSize: 10,
       },
     });
@@ -158,7 +157,7 @@ describe('e2e_p2p_add_rollup', () => {
         aztecTargetCommitteeSize: t.ctx.aztecNodeConfig.aztecTargetCommitteeSize,
         aztecProofSubmissionEpochs: t.ctx.aztecNodeConfig.aztecProofSubmissionEpochs,
         slashingQuorum: t.ctx.aztecNodeConfig.slashingQuorum,
-        slashingRoundSize: t.ctx.aztecNodeConfig.slashingRoundSize,
+        slashingRoundSizeInEpochs: t.ctx.aztecNodeConfig.slashingRoundSizeInEpochs,
         slashingLifetimeInRounds: t.ctx.aztecNodeConfig.slashingLifetimeInRounds,
         slashingExecutionDelayInRounds: t.ctx.aztecNodeConfig.slashingExecutionDelayInRounds,
         slashingVetoer: t.ctx.aztecNodeConfig.slashingVetoer,
diff --git a/yarn-project/end-to-end/src/e2e_p2p/data_withholding_slash.test.ts b/yarn-project/end-to-end/src/e2e_p2p/data_withholding_slash.test.ts
index e6e521a452ba..e99ccd4e012f 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/data_withholding_slash.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/data_withholding_slash.test.ts
@@ -58,7 +58,7 @@ describe('e2e_p2p_data_withholding_slash', () => {
         aztecSlotDuration,
         aztecProofSubmissionEpochs: 0, // effectively forces instant reorgs
         slashingQuorum,
-        slashingRoundSize,
+        slashingRoundSizeInEpochs: slashingRoundSize / 2,
         slashAmountSmall: slashingUnit,
         slashAmountMedium: slashingUnit * 2n,
         slashAmountLarge: slashingUnit * 3n,
diff --git a/yarn-project/end-to-end/src/e2e_p2p/gossip_network.test.ts b/yarn-project/end-to-end/src/e2e_p2p/gossip_network.test.ts
index e8c34a75ad64..1ca696ff3acf 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/gossip_network.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/gossip_network.test.ts
@@ -59,7 +59,7 @@ describe('e2e_p2p_network', () => {
       initialConfig: {
         ...SHORTENED_BLOCK_TIME_CONFIG_NO_PRUNES,
         aztecEpochDuration: 4,
-        slashingRoundSize: 8,
+        slashingRoundSizeInEpochs: 2,
         slashingQuorum: 5,
         listenAddress: '127.0.0.1',
       },
diff --git a/yarn-project/end-to-end/src/e2e_p2p/inactivity_slash.test.ts b/yarn-project/end-to-end/src/e2e_p2p/inactivity_slash.test.ts
index bcad2157a6e1..2133a5028a6c 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/inactivity_slash.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/inactivity_slash.test.ts
@@ -41,7 +41,7 @@ describe('e2e_p2p_inactivity_slash', () => {
       basePort: BOOT_NODE_UDP_PORT,
       startProverNode: true,
       initialConfig: {
-        aztecTargetCommitteeSize: NUM_NODES, // ensure we can progress even after slash happens
+        aztecTargetCommitteeSize: NUM_VALIDATORS,
         aztecSlotDuration: AZTEC_SLOT_DURATION,
         ethereumSlotDuration: ETHEREUM_SLOT_DURATION,
         aztecProofSubmissionEpochs: 1024, // effectively do not reorg
@@ -51,7 +51,7 @@ describe('e2e_p2p_inactivity_slash', () => {
         validatorReexecute: false,
         sentinelEnabled: true,
         slashingQuorum: SLASHING_QUORUM,
-        slashingRoundSize: SLASHING_ROUND_SIZE,
+        slashingRoundSizeInEpochs: SLASHING_ROUND_SIZE / EPOCH_DURATION,
         slashInactivityTargetPercentage: 0.5,
         slashAmountSmall: SLASHING_UNIT,
         slashAmountMedium: SLASHING_UNIT * 2n,
diff --git a/yarn-project/end-to-end/src/e2e_p2p/p2p_network.ts b/yarn-project/end-to-end/src/e2e_p2p/p2p_network.ts
index 6391b7916169..b46588d6be60 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/p2p_network.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/p2p_network.ts
@@ -116,7 +116,8 @@ export class P2PNetworkTest {
         aztecSlotDuration: initialValidatorConfig.aztecSlotDuration ?? l1ContractsConfig.aztecSlotDuration,
         aztecProofSubmissionEpochs:
           initialValidatorConfig.aztecProofSubmissionEpochs ?? l1ContractsConfig.aztecProofSubmissionEpochs,
-        slashingRoundSize: initialValidatorConfig.slashingRoundSize ?? l1ContractsConfig.slashingRoundSize,
+        slashingRoundSizeInEpochs:
+          initialValidatorConfig.slashingRoundSizeInEpochs ?? l1ContractsConfig.slashingRoundSizeInEpochs,
         slasherFlavor: initialValidatorConfig.slasherFlavor ?? 'tally',
         aztecTargetCommitteeSize: numberOfValidators,
         salt: 420,
@@ -127,7 +128,8 @@ export class P2PNetworkTest {
       {
         ...initialValidatorConfig,
         aztecEpochDuration: initialValidatorConfig.aztecEpochDuration ?? l1ContractsConfig.aztecEpochDuration,
-        slashingRoundSize: initialValidatorConfig.slashingRoundSize ?? l1ContractsConfig.slashingRoundSize,
+        slashingRoundSizeInEpochs:
+          initialValidatorConfig.slashingRoundSizeInEpochs ?? l1ContractsConfig.slashingRoundSizeInEpochs,
         slasherFlavor: initialValidatorConfig.slasherFlavor ?? 'tally',
 
         ethereumSlotDuration: initialValidatorConfig.ethereumSlotDuration ?? l1ContractsConfig.ethereumSlotDuration,
diff --git a/yarn-project/end-to-end/src/e2e_p2p/reqresp.test.ts b/yarn-project/end-to-end/src/e2e_p2p/reqresp.test.ts
index 4d1a7955e5ce..8bbe5f95d762 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/reqresp.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/reqresp.test.ts
@@ -36,8 +36,6 @@ describe('e2e_p2p_reqresp_tx', () => {
         ...SHORTENED_BLOCK_TIME_CONFIG_NO_PRUNES,
         listenAddress: '127.0.0.1',
         aztecEpochDuration: 64, // stable committee
-        slashingRoundSize: 128,
-        slashingQuorum: 65,
       },
     });
     await t.applyBaseSnapshots();
diff --git a/yarn-project/end-to-end/src/e2e_p2p/reqresp_no_handshake.test.ts b/yarn-project/end-to-end/src/e2e_p2p/reqresp_no_handshake.test.ts
index 7aa979421a41..d15186aa4dc8 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/reqresp_no_handshake.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/reqresp_no_handshake.test.ts
@@ -41,8 +41,6 @@ describe('e2e_p2p_reqresp_tx_no_handshake', () => {
         p2pDisableStatusHandshake: true, // DIFFERENCE FROM reqresp.test.ts
         listenAddress: '127.0.0.1',
         aztecEpochDuration: 64, // stable committee
-        slashingRoundSize: 128,
-        slashingQuorum: 65,
       },
     });
     await t.applyBaseSnapshots();
diff --git a/yarn-project/end-to-end/src/e2e_p2p/slash_veto_demo.test.ts b/yarn-project/end-to-end/src/e2e_p2p/slash_veto_demo.test.ts
index cc18ccb73fa3..997ce45f7208 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/slash_veto_demo.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/slash_veto_demo.test.ts
@@ -88,7 +88,7 @@ describe('veto slash', () => {
         slashAmountSmall: SLASHING_UNIT,
         slashAmountMedium: SLASHING_UNIT * 2n,
         slashAmountLarge: SLASHING_UNIT * 3n,
-        slashingRoundSize: SLASHING_ROUND_SIZE,
+        slashingRoundSizeInEpochs: SLASHING_ROUND_SIZE / EPOCH_DURATION,
         slashingQuorum: SLASHING_QUORUM,
         slashInactivityTargetPercentage: SLASH_INACTIVITY_TARGET_PERCENTAGE,
       },
diff --git a/yarn-project/end-to-end/src/e2e_p2p/upgrade_governance_proposer.test.ts b/yarn-project/end-to-end/src/e2e_p2p/upgrade_governance_proposer.test.ts
index c23bbfc01b71..40c4ab46b75e 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/upgrade_governance_proposer.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/upgrade_governance_proposer.test.ts
@@ -48,7 +48,6 @@ describe('e2e_p2p_governance_proposer', () => {
       initialConfig: {
         ...SHORTENED_BLOCK_TIME_CONFIG_NO_PRUNES,
         listenAddress: '127.0.0.1',
-        governanceProposerQuorum: 6,
         governanceProposerRoundSize: 10,
         activationThreshold: 10n ** 22n,
         ejectionThreshold: 5n ** 22n,
diff --git a/yarn-project/end-to-end/src/e2e_p2p/valid_epoch_pruned.test.ts b/yarn-project/end-to-end/src/e2e_p2p/valid_epoch_pruned.test.ts
index 0b9e2cfbe6d1..9e2e08cd59e6 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/valid_epoch_pruned.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/valid_epoch_pruned.test.ts
@@ -48,7 +48,7 @@ describe('e2e_p2p_valid_epoch_pruned', () => {
         aztecSlotDuration,
         aztecProofSubmissionEpochs: 0, // reorg as soon as epoch ends
         slashingQuorum,
-        slashingRoundSize,
+        slashingRoundSizeInEpochs: slashingRoundSize / 2,
         slashSelfAllowed: true,
         slashAmountSmall: slashingUnit,
         slashAmountMedium: slashingUnit * 2n,
diff --git a/yarn-project/end-to-end/src/e2e_p2p/validators_sentinel.test.ts b/yarn-project/end-to-end/src/e2e_p2p/validators_sentinel.test.ts
index a595def9d68b..ca3c75ec3237 100644
--- a/yarn-project/end-to-end/src/e2e_p2p/validators_sentinel.test.ts
+++ b/yarn-project/end-to-end/src/e2e_p2p/validators_sentinel.test.ts
@@ -44,8 +44,7 @@ describe('e2e_p2p_validators_sentinel', () => {
         listenAddress: '127.0.0.1',
         minTxsPerBlock: 0,
         aztecEpochDuration: EPOCH_DURATION,
-        slashingRoundSize: EPOCH_DURATION * 2,
-        slashingQuorum: EPOCH_DURATION + 1,
+        slashingRoundSizeInEpochs: 2,
         validatorReexecute: false,
         sentinelEnabled: true,
         slashInactivityPenalty: 0n, // Set to 0 to disable
diff --git a/yarn-project/end-to-end/src/fixtures/snapshot_manager.ts b/yarn-project/end-to-end/src/fixtures/snapshot_manager.ts
index baef91c39bac..7d99d3ccb8ce 100644
--- a/yarn-project/end-to-end/src/fixtures/snapshot_manager.ts
+++ b/yarn-project/end-to-end/src/fixtures/snapshot_manager.ts
@@ -306,9 +306,13 @@ async function setupFromFresh(
 
   const blobSinkPort = await getPort();
 
+  // Default to no slashing
+  opts.slasherFlavor ??= 'none';
+  deployL1ContractsArgs.slasherFlavor ??= opts.slasherFlavor;
+
   // Fetch the AztecNode config.
   // TODO: For some reason this is currently the union of a bunch of subsystems. That needs fixing.
-  const aztecNodeConfig: AztecNodeConfig & SetupOptions = { ...getConfigEnvVars(), slasherFlavor: 'none', ...opts };
+  const aztecNodeConfig: AztecNodeConfig & SetupOptions = { ...getConfigEnvVars(), ...opts };
   aztecNodeConfig.peerCheckIntervalMS = TEST_PEER_CHECK_INTERVAL_MS;
   aztecNodeConfig.maxTxPoolSize = opts.maxTxPoolSize ?? TEST_MAX_TX_POOL_SIZE;
   // Only enable proving if specifically requested.
diff --git a/yarn-project/end-to-end/src/fixtures/utils.ts b/yarn-project/end-to-end/src/fixtures/utils.ts
index 8458cb380904..f5866420f3b3 100644
--- a/yarn-project/end-to-end/src/fixtures/utils.ts
+++ b/yarn-project/end-to-end/src/fixtures/utils.ts
@@ -391,8 +391,9 @@ export async function setup(
   let anvil: Anvil | undefined;
   try {
     opts.aztecTargetCommitteeSize ??= 0;
+    opts.slasherFlavor ??= 'none';
 
-    const config: AztecNodeConfig & SetupOptions = { ...getConfigEnvVars(), slasherFlavor: 'none', ...opts };
+    const config: AztecNodeConfig & SetupOptions = { ...getConfigEnvVars(), ...opts };
     // use initialValidators for the node config
     config.validatorPrivateKeys = new SecretValue(opts.initialValidators?.map(v => v.privateKey) ?? []);
 
diff --git a/yarn-project/end-to-end/src/spartan/upgrade_rollup_version.test.ts b/yarn-project/end-to-end/src/spartan/upgrade_rollup_version.test.ts
index b671496fb31e..65320d359953 100644
--- a/yarn-project/end-to-end/src/spartan/upgrade_rollup_version.test.ts
+++ b/yarn-project/end-to-end/src/spartan/upgrade_rollup_version.test.ts
@@ -95,7 +95,7 @@
 //           aztecProofSubmissionEpochs: 1,
 //           aztecTargetCommitteeSize: 48,
 //           slashingQuorum: 5,
-//           slashingRoundSize: 8,
+//           slashingRoundSizeInEpochs: 2,
 //           slashingLifetimeInRounds: 5,
 //           slashingExecutionDelayInRounds: 0,
 //           slashingVetoer: EthAddress.ZERO,
diff --git a/yarn-project/ethereum/src/config.ts b/yarn-project/ethereum/src/config.ts
index ab00b9fc93fb..cabebf4ed222 100644
--- a/yarn-project/ethereum/src/config.ts
+++ b/yarn-project/ethereum/src/config.ts
@@ -6,6 +6,7 @@ import {
   enumConfigHelper,
   getConfigFromMappings,
   numberConfigHelper,
+  optionalNumberConfigHelper,
 } from '@aztec/foundation/config';
 import { EthAddress } from '@aztec/foundation/eth-address';
 
@@ -33,10 +34,10 @@ export type L1ContractsConfig = {
   activationThreshold: bigint;
   /** The minimum stake for a validator. */
   ejectionThreshold: bigint;
-  /** The slashing quorum, i.e. how many slots must signal for the same payload in a round for it to be submittable to the Slasher */
-  slashingQuorum: number;
-  /** The slashing round size, i.e. how many slots are in a round */
-  slashingRoundSize: number;
+  /** The slashing quorum, i.e. how many slots must signal for the same payload in a round for it to be submittable to the Slasher (defaults to slashRoundSize / 2 + 1) */
+  slashingQuorum?: number;
+  /** The slashing round size, i.e. how many epochs are in a slashing round */
+  slashingRoundSizeInEpochs: number;
   /** The slashing lifetime in rounds. I.e., if 1, round N must be submitted before round N + 2 */
   slashingLifetimeInRounds: number;
   /** The slashing execution delay in rounds. I.e., if 1, round N may not be submitted until round N + 2 */
@@ -53,8 +54,8 @@ export type L1ContractsConfig = {
   slashAmountMedium: bigint;
   /** Largest amount that can be slashed per round in tally slashing */
   slashAmountLarge: bigint;
-  /** Governance proposing quorum */
-  governanceProposerQuorum: number;
+  /** Governance proposing quorum (defaults to roundSize/2 + 1) */
+  governanceProposerQuorum?: number;
   /** Governance proposing round size */
   governanceProposerRoundSize: number;
   /** The mana target for the rollup */
@@ -76,12 +77,10 @@ export const DefaultL1ContractsConfig = {
   slashAmountSmall: BigInt(10e18),
   slashAmountMedium: BigInt(20e18),
   slashAmountLarge: BigInt(50e18),
-  slashingRoundSize: 32 * 6, // 6 epochs
-  slashingQuorum: (32 * 6) / 2 + 1, // 6 epochs, majority of validators
+  slashingRoundSizeInEpochs: 4,
   slashingLifetimeInRounds: 5,
   slashingExecutionDelayInRounds: 0, // round N may be submitted in round N + 1
   slashingVetoer: EthAddress.ZERO,
-  governanceProposerQuorum: 151,
   governanceProposerRoundSize: 300,
   manaTarget: BigInt(1e10),
   provingCostPerMana: BigInt(100),
@@ -278,12 +277,12 @@ export const l1ContractsConfigMappings: ConfigMappingsType<L1ContractsConfig> =
   slashingQuorum: {
     env: 'AZTEC_SLASHING_QUORUM',
     description: 'The slashing quorum',
-    ...numberConfigHelper(DefaultL1ContractsConfig.slashingQuorum),
+    ...optionalNumberConfigHelper(),
   },
-  slashingRoundSize: {
-    env: 'AZTEC_SLASHING_ROUND_SIZE',
+  slashingRoundSizeInEpochs: {
+    env: 'AZTEC_SLASHING_ROUND_SIZE_IN_EPOCHS',
     description: 'The slashing round size',
-    ...numberConfigHelper(DefaultL1ContractsConfig.slashingRoundSize),
+    ...numberConfigHelper(DefaultL1ContractsConfig.slashingRoundSizeInEpochs),
   },
   slashingLifetimeInRounds: {
     env: 'AZTEC_SLASHING_LIFETIME_IN_ROUNDS',
@@ -304,7 +303,7 @@ export const l1ContractsConfigMappings: ConfigMappingsType<L1ContractsConfig> =
   governanceProposerQuorum: {
     env: 'AZTEC_GOVERNANCE_PROPOSER_QUORUM',
     description: 'The governance proposing quorum',
-    ...numberConfigHelper(DefaultL1ContractsConfig.governanceProposerQuorum),
+    ...optionalNumberConfigHelper(),
   },
   governanceProposerRoundSize: {
     env: 'AZTEC_GOVERNANCE_PROPOSER_ROUND_SIZE',
@@ -349,3 +348,196 @@ export function getL1ContractsConfigEnvVars(): L1ContractsConfig {
 export function getGenesisStateConfigEnvVars(): GenesisStateConfig {
   return getConfigFromMappings(genesisStateConfigMappings);
 }
+
+/**
+ * Validates the L1 contracts configuration to ensure all requirements enforced by L1 contracts
+ * during construction are satisfied before deployment.
+ * Accumulates all validation errors and throws an exception listing them all if any are found.
+ */
+export function validateConfig(config: Omit<L1ContractsConfig, keyof L1TxUtilsConfig>): void {
+  const errors: string[] = [];
+
+  // RollupCore constructor validation: normalFlushSizeMin > 0
+  // From: require(_config.stakingQueueConfig.normalFlushSizeMin > 0, Errors.Staking__InvalidStakingQueueConfig());
+  const entryQueueConfig = getEntryQueueConfig('testnet'); // Get config to check normalFlushSizeMin
+  if (entryQueueConfig.normalFlushSizeMin <= 0n) {
+    errors.push('normalFlushSizeMin must be greater than 0');
+  }
+
+  // TimeLib initialization validation: aztecSlotDuration should be a multiple of ethereumSlotDuration
+  // While not explicitly required in constructor, this is a common validation for time-based systems
+  if (config.aztecSlotDuration % config.ethereumSlotDuration !== 0) {
+    errors.push(
+      `aztecSlotDuration (${config.aztecSlotDuration}) must be a multiple of ethereumSlotDuration (${config.ethereumSlotDuration})`,
+    );
+  }
+
+  // EmpireBase constructor validations for governance/slashing proposers
+  // From: require(QUORUM_SIZE > ROUND_SIZE / 2, Errors.GovernanceProposer__InvalidQuorumAndRoundSize(QUORUM_SIZE, ROUND_SIZE));
+  const { governanceProposerQuorum, governanceProposerRoundSize } = config;
+  if (
+    governanceProposerQuorum !== undefined &&
+    governanceProposerQuorum <= Math.floor(governanceProposerRoundSize / 2)
+  ) {
+    errors.push(
+      `governanceProposerQuorum (${governanceProposerQuorum}) must be greater than half of governanceProposerRoundSize (${Math.floor(governanceProposerRoundSize / 2)})`,
+    );
+  }
+
+  // From: require(QUORUM_SIZE <= ROUND_SIZE, Errors.GovernanceProposer__QuorumCannotBeLargerThanRoundSize(QUORUM_SIZE, ROUND_SIZE));
+  if (governanceProposerQuorum !== undefined && governanceProposerQuorum > governanceProposerRoundSize) {
+    errors.push(
+      `governanceProposerQuorum (${governanceProposerQuorum}) cannot be larger than governanceProposerRoundSize (${governanceProposerRoundSize})`,
+    );
+  }
+
+  // Slashing quorum validations (similar to governance quorum)
+  const slashingRoundSize = config.slashingRoundSizeInEpochs * config.aztecEpochDuration;
+  const { slashingQuorum } = config;
+  if (slashingQuorum !== undefined && slashingQuorum <= Math.floor(slashingRoundSize / 2)) {
+    errors.push(
+      `slashingQuorum (${slashingQuorum}) must be greater than half of slashingRoundSizeInEpochs (${Math.floor(slashingRoundSize / 2)})`,
+    );
+  }
+
+  if (slashingQuorum !== undefined && slashingQuorum > slashingRoundSize) {
+    errors.push(
+      `slashingQuorum (${slashingQuorum}) cannot be larger than slashingRoundSizeInEpochs (${slashingRoundSize})`,
+    );
+  }
+
+  // EmpireBase and TallySlashingProposer lifetime and execution delay validation
+  // From: require(LIFETIME_IN_ROUNDS > EXECUTION_DELAY_IN_ROUNDS);
+  if (config.slashingLifetimeInRounds <= config.slashingExecutionDelayInRounds) {
+    errors.push(
+      `slashingLifetimeInRounds (${config.slashingLifetimeInRounds}) must be greater than slashingExecutionDelayInRounds (${config.slashingExecutionDelayInRounds})`,
+    );
+  }
+
+  // Staking asset validation: activationThreshold > ejectionThreshold
+  if (config.activationThreshold < config.ejectionThreshold) {
+    errors.push(
+      `activationThreshold (${config.activationThreshold}) must be greater than ejectionThreshold (${config.ejectionThreshold})`,
+    );
+  }
+
+  // TallySlashingProposer constructor validations
+  if (config.slasherFlavor === 'tally') {
+    // From: require(SLASH_OFFSET_IN_ROUNDS > 0, Errors.TallySlashingProposer__SlashOffsetMustBeGreaterThanZero(...));
+    if (config.slashingOffsetInRounds <= 0) {
+      errors.push(`slashingOffsetInRounds (${config.slashingOffsetInRounds}) must be greater than 0`);
+    }
+
+    // From: require(ROUND_SIZE_IN_EPOCHS * _epochDuration == ROUND_SIZE, Errors.TallySlashingProposer__RoundSizeMustBeMultipleOfEpochDuration(...));
+    const roundSizeInSlots = config.slashingRoundSizeInEpochs * config.aztecEpochDuration;
+
+    // From: require(QUORUM > 0, Errors.TallySlashingProposer__QuorumMustBeGreaterThanZero());
+    if (slashingQuorum !== undefined && slashingQuorum <= 0) {
+      errors.push(`slashingQuorum (${slashingQuorum}) must be greater than 0`);
+    }
+
+    // From: require(ROUND_SIZE > 1, Errors.TallySlashingProposer__InvalidQuorumAndRoundSize(QUORUM, ROUND_SIZE));
+    if (roundSizeInSlots <= 1) {
+      errors.push(`slashing round size in slots (${roundSizeInSlots}) must be greater than 1`);
+    }
+
+    // From: require(_slashAmounts[0] <= _slashAmounts[1], Errors.TallySlashingProposer__InvalidSlashAmounts(_slashAmounts));
+    if (config.slashAmountSmall > config.slashAmountMedium) {
+      errors.push(
+        `slashAmountSmall (${config.slashAmountSmall}) must be less than or equal to slashAmountMedium (${config.slashAmountMedium})`,
+      );
+    }
+
+    // From: require(_slashAmounts[1] <= _slashAmounts[2], Errors.TallySlashingProposer__InvalidSlashAmounts(_slashAmounts));
+    if (config.slashAmountMedium > config.slashAmountLarge) {
+      errors.push(
+        `slashAmountMedium (${config.slashAmountMedium}) must be less than or equal to slashAmountLarge (${config.slashAmountLarge})`,
+      );
+    }
+
+    // From: require(LIFETIME_IN_ROUNDS < ROUNDABOUT_SIZE, Errors.TallySlashingProposer__LifetimeMustBeLessThanRoundabout(...));
+    const ROUNDABOUT_SIZE = 128; // Constant from TallySlashingProposer
+    if (config.slashingLifetimeInRounds >= ROUNDABOUT_SIZE) {
+      errors.push(`slashingLifetimeInRounds (${config.slashingLifetimeInRounds}) must be less than ${ROUNDABOUT_SIZE}`);
+    }
+
+    // From: require(ROUND_SIZE_IN_EPOCHS > 0, Errors.TallySlashingProposer__RoundSizeInEpochsMustBeGreaterThanZero(...));
+    if (config.slashingRoundSizeInEpochs <= 0) {
+      errors.push(`slashingRoundSizeInEpochs (${config.slashingRoundSizeInEpochs}) must be greater than 0`);
+    }
+
+    // From: require(ROUND_SIZE < MAX_ROUND_SIZE, Errors.TallySlashingProposer__RoundSizeTooLarge(ROUND_SIZE, MAX_ROUND_SIZE));
+    const MAX_ROUND_SIZE = 1024; // Constant from TallySlashingProposer
+    if (roundSizeInSlots >= MAX_ROUND_SIZE) {
+      errors.push(`slashing round size in slots (${roundSizeInSlots}) must be less than ${MAX_ROUND_SIZE}`);
+    }
+
+    // From: require(COMMITTEE_SIZE > 0, Errors.TallySlashingProposer__CommitteeSizeMustBeGreaterThanZero(COMMITTEE_SIZE));
+    if (config.aztecTargetCommitteeSize <= 0) {
+      errors.push(`aztecTargetCommitteeSize (${config.aztecTargetCommitteeSize}) must be greater than 0`);
+    }
+
+    // From: require(voteSize <= 128, Errors.TallySlashingProposer__VoteSizeTooBig(voteSize, 128));
+    // voteSize = COMMITTEE_SIZE * ROUND_SIZE_IN_EPOCHS / 4
+    const voteSize = (config.aztecTargetCommitteeSize * config.slashingRoundSizeInEpochs) / 4;
+    if (voteSize > 128) {
+      errors.push(`vote size (${voteSize}) must be <= 128 (committee size * round size in epochs / 4)`);
+    }
+
+    // From: require(COMMITTEE_SIZE * ROUND_SIZE_IN_EPOCHS % 4 == 0, Errors.TallySlashingProposer__InvalidCommitteeAndRoundSize(...));
+    if ((config.aztecTargetCommitteeSize * config.slashingRoundSizeInEpochs) % 4 !== 0) {
+      errors.push(
+        `aztecTargetCommitteeSize * slashingRoundSizeInEpochs (${config.aztecTargetCommitteeSize * config.slashingRoundSizeInEpochs}) must be divisible by 4`,
+      );
+    }
+
+    // Slashing offset validation: should be positive to allow proper slashing timing
+    if (config.slashingOffsetInRounds < 0) {
+      errors.push('slashingOffsetInRounds cannot be negative');
+    }
+  }
+
+  // Epoch and slot duration validations
+  if (config.aztecSlotDuration <= 0) {
+    errors.push('aztecSlotDuration must be greater than 0');
+  }
+
+  if (config.ethereumSlotDuration <= 0) {
+    errors.push('ethereumSlotDuration must be greater than 0');
+  }
+
+  if (config.aztecEpochDuration <= 0) {
+    errors.push('aztecEpochDuration must be greater than 0');
+  }
+
+  // Committee size validation
+  if (config.aztecTargetCommitteeSize < 0) {
+    errors.push('aztecTargetCommitteeSize cannot be negative');
+  }
+
+  // Proof submission epochs validation
+  if (config.aztecProofSubmissionEpochs < 0) {
+    errors.push('aztecProofSubmissionEpochs cannot be negative');
+  }
+
+  // Exit delay validation
+  if (config.exitDelaySeconds < 0) {
+    errors.push('exitDelaySeconds cannot be negative');
+  }
+
+  // Mana validation
+  if (config.manaTarget < 0n) {
+    errors.push('manaTarget cannot be negative');
+  }
+
+  if (config.provingCostPerMana < 0n) {
+    errors.push('provingCostPerMana cannot be negative');
+  }
+
+  // If any errors were found, throw an exception with all of them
+  if (errors.length > 0) {
+    throw new Error(
+      `L1 contracts configuration validation failed with ${errors.length} error(s):\n${errors.map((error, index) => `${index + 1}. ${error}`).join('\n')}`,
+    );
+  }
+}
diff --git a/yarn-project/ethereum/src/contracts/tally_slashing_proposer.test.ts b/yarn-project/ethereum/src/contracts/tally_slashing_proposer.test.ts
index e09e9f1002bc..30e337f62175 100644
--- a/yarn-project/ethereum/src/contracts/tally_slashing_proposer.test.ts
+++ b/yarn-project/ethereum/src/contracts/tally_slashing_proposer.test.ts
@@ -65,7 +65,8 @@ describe('TallySlashingProposer', () => {
       genesisArchiveRoot: Fr.random(),
       realVerifier: false,
       slasherFlavor: 'tally' as const,
-      slashingRoundSize: testSlashingRoundSize,
+      slashingQuorum: testSlashingRoundSize / 2 + 1,
+      slashingRoundSizeInEpochs: testSlashingRoundSize / DefaultL1ContractsConfig.aztecEpochDuration,
       aztecTargetCommitteeSize: 4,
       initialValidators: validatorsAddresses.map(attester => ({
         attester,
@@ -96,12 +97,12 @@ describe('TallySlashingProposer', () => {
   describe('contract constants getters', () => {
     it('returns correct quorum size from deployed contract', async () => {
       const quorumSize = await tallySlashingProposer.getQuorumSize();
-      expect(quorumSize).toBe(BigInt(testConfig.slashingQuorum));
+      expect(quorumSize).toBe(BigInt(testConfig.slashingQuorum!));
     });
 
     it('returns correct round size from deployed contract', async () => {
       const roundSize = await tallySlashingProposer.getRoundSize();
-      expect(roundSize).toBe(BigInt(testConfig.slashingRoundSize));
+      expect(roundSize).toBe(BigInt(testConfig.slashingRoundSizeInEpochs * testConfig.aztecEpochDuration));
     });
 
     it('returns correct committee size from deployed contract', async () => {
@@ -111,7 +112,7 @@ describe('TallySlashingProposer', () => {
 
     it('returns correct round size in epochs from deployed contract', async () => {
       const roundSizeInEpochs = await tallySlashingProposer.getRoundSizeInEpochs();
-      const expectedValue = BigInt(testConfig.slashingRoundSize / testConfig.aztecEpochDuration);
+      const expectedValue = BigInt(testConfig.slashingRoundSizeInEpochs);
       expect(roundSizeInEpochs).toBe(expectedValue);
     });
 
diff --git a/yarn-project/ethereum/src/deploy_l1_contracts.ts b/yarn-project/ethereum/src/deploy_l1_contracts.ts
index 4b9f7d880366..053ed72603a4 100644
--- a/yarn-project/ethereum/src/deploy_l1_contracts.ts
+++ b/yarn-project/ethereum/src/deploy_l1_contracts.ts
@@ -34,6 +34,7 @@ import {
   getGovernanceConfiguration,
   getRewardBoostConfig,
   getRewardConfig,
+  validateConfig,
 } from './config.js';
 import { GSEContract } from './contracts/gse.js';
 import { deployMulticall3 } from './contracts/multicall.js';
@@ -128,7 +129,7 @@ export interface ContractArtifacts<TAbi extends Abi | readonly unknown[] = Abi>
   libraries?: Libraries;
 }
 
-export interface DeployL1ContractsArgs extends L1ContractsConfig {
+export interface DeployL1ContractsArgs extends Omit<L1ContractsConfig, keyof L1TxUtilsConfig> {
   /** The vk tree root. */
   vkTreeRoot: Fr;
   /** The protocol contract tree root. */
@@ -195,7 +196,7 @@ export const deploySharedContracts = async (
   const governanceProposerAddress = await deployer.deploy(GovernanceProposerArtifact, [
     registryAddress.toString(),
     gseAddress.toString(),
-    BigInt(args.governanceProposerQuorum),
+    BigInt(args.governanceProposerQuorum ?? args.governanceProposerRoundSize / 2 + 1),
     BigInt(args.governanceProposerRoundSize),
   ]);
   logger.verbose(`Deployed GovernanceProposer at ${governanceProposerAddress}`);
@@ -531,8 +532,8 @@ export const deployRollup = async (
     aztecEpochDuration: BigInt(args.aztecEpochDuration),
     targetCommitteeSize: BigInt(args.aztecTargetCommitteeSize),
     aztecProofSubmissionEpochs: BigInt(args.aztecProofSubmissionEpochs),
-    slashingQuorum: BigInt(args.slashingQuorum),
-    slashingRoundSize: BigInt(args.slashingRoundSize),
+    slashingQuorum: BigInt(args.slashingQuorum ?? (args.slashingRoundSizeInEpochs * args.aztecEpochDuration) / 2 + 1),
+    slashingRoundSize: BigInt(args.slashingRoundSizeInEpochs * args.aztecEpochDuration),
     slashingLifetimeInRounds: BigInt(args.slashingLifetimeInRounds),
     slashingExecutionDelayInRounds: BigInt(args.slashingExecutionDelayInRounds),
     slashingVetoer: args.slashingVetoer.toString(),
@@ -914,6 +915,8 @@ export const deployL1Contracts = async (
   args: DeployL1ContractsArgs,
   txUtilsConfig: L1TxUtilsConfig = getL1TxUtilsConfigEnvVars(),
 ): Promise<DeployL1ContractsReturnType> => {
+  validateConfig(args);
+
   const l1Client = createExtendedL1Client(rpcUrls, account, chain);
 
   // Deploy multicall3 if it does not exist in this network
diff --git a/yarn-project/ethereum/src/queries.ts b/yarn-project/ethereum/src/queries.ts
index e0ebf066be90..fd84a44090d0 100644
--- a/yarn-project/ethereum/src/queries.ts
+++ b/yarn-project/ethereum/src/queries.ts
@@ -90,7 +90,7 @@ export async function getL1ContractsConfig(
     activationThreshold,
     ejectionThreshold,
     slashingQuorum: Number(slashingQuorum),
-    slashingRoundSize: Number(slashingRoundSize),
+    slashingRoundSizeInEpochs: Number(slashingRoundSize / aztecEpochDuration),
     slashingLifetimeInRounds: Number(slashingLifetimeInRounds),
     slashingExecutionDelayInRounds: Number(slashingExecutionDelayInRounds),
     slashingVetoer: EthAddress.fromString(slashingVetoer),
diff --git a/yarn-project/foundation/src/config/env_var.ts b/yarn-project/foundation/src/config/env_var.ts
index 9316e771dd6e..9f3619f11839 100644
--- a/yarn-project/foundation/src/config/env_var.ts
+++ b/yarn-project/foundation/src/config/env_var.ts
@@ -262,7 +262,7 @@ export type EnvVar =
   | 'AZTEC_MANA_TARGET'
   | 'AZTEC_PROVING_COST_PER_MANA'
   | 'AZTEC_SLASHING_QUORUM'
-  | 'AZTEC_SLASHING_ROUND_SIZE'
+  | 'AZTEC_SLASHING_ROUND_SIZE_IN_EPOCHS'
   | 'AZTEC_SLASHING_LIFETIME_IN_ROUNDS'
   | 'AZTEC_SLASHING_EXECUTION_DELAY_IN_ROUNDS'
   | 'AZTEC_SLASHING_VETOER'
diff --git a/yarn-project/slasher/src/slash_round_monitor.ts b/yarn-project/slasher/src/slash_round_monitor.ts
index ca95c0a9bc51..d5a9dfdb636a 100644
--- a/yarn-project/slasher/src/slash_round_monitor.ts
+++ b/yarn-project/slasher/src/slash_round_monitor.ts
@@ -1,4 +1,3 @@
-import type { L1ContractsConfig } from '@aztec/ethereum';
 import { createLogger } from '@aztec/foundation/log';
 import type { DateProvider } from '@aztec/foundation/timer';
 import type { Prettify } from '@aztec/foundation/types';
@@ -6,8 +5,7 @@ import { type L1RollupConstants, getSlotAtTimestamp } from '@aztec/stdlib/epoch-
 import { getRoundForSlot } from '@aztec/stdlib/slashing';
 
 export type SlashRoundMonitorSettings = Prettify<
-  Pick<L1RollupConstants, 'epochDuration' | 'l1GenesisTime' | 'slotDuration'> &
-    Pick<L1ContractsConfig, 'slashingRoundSize'>
+  Pick<L1RollupConstants, 'epochDuration' | 'l1GenesisTime' | 'slotDuration'> & { slashingRoundSize: number }
 >;
 
 export class SlashRoundMonitor {
@@ -16,8 +14,7 @@ export class SlashRoundMonitor {
   private handler: ((round: bigint) => Promise<void>) | undefined = undefined;
 
   constructor(
-    private settings: Pick<L1RollupConstants, 'epochDuration' | 'l1GenesisTime' | 'slotDuration'> &
-      Pick<L1ContractsConfig, 'slashingRoundSize'>,
+    private settings: SlashRoundMonitorSettings,
     private dateProvider: DateProvider,
     private log = createLogger('slasher:round-monitor'),
   ) {}