diff --git a/lib/mining/common.js b/lib/mining/common.js
index bc677df6..e2bff308 100644
--- a/lib/mining/common.js
+++ b/lib/mining/common.js
@@ -7,6 +7,8 @@
 'use strict';
 
 var assert = require('assert');
+var consensus = require('../protocol/consensus');
+var BN = require('bn.js');
 
 /**
  * @exports mining/common
@@ -18,7 +20,7 @@ var common = exports;
  * Constants
  */
 
-var DIFF_TARGET = 0x00000000ffff0000000000000000000000000000000000000000000000000000;
+var DIFF = 0x00000000ffff0000000000000000000000000000000000000000000000000000;
 var B192 = 0x1000000000000000000000000000000000000000000000000;
 var B128 = 0x100000000000000000000000000000000;
 var B64 = 0x10000000000000000;
@@ -30,7 +32,7 @@ var B0 = 0x1;
  * @returns {Buffer}
  */
 
-exports.swap32 = function swap32(data) {
+common.swap32 = function swap32(data) {
   var i, field;
 
   for (i = 0; i < data.length; i += 4) {
@@ -43,14 +45,13 @@ exports.swap32 = function swap32(data) {
 
 /**
  * Swap 32 bit endianness of uint256 (hex).
- * @param {String} data
+ * @param {String} str
  * @returns {String}
  */
 
-exports.hswap32 = function hswap32(hex) {
-  var data = new Buffer(hex, 'hex');
-  exports.swap32(data)
-  return data.toString('hex');
+common.swap32hex = function swap32hex(str) {
+  var data = new Buffer(str, 'hex');
+  return common.swap32(data).toString('hex');
 };
 
 /**
@@ -60,7 +61,7 @@ exports.hswap32 = function hswap32(hex) {
  * @returns {Number}
  */
 
-exports.rcmp = function rcmp(a, b) {
+common.rcmp = function rcmp(a, b) {
   var i;
 
   assert(a.length === b.length);
@@ -81,7 +82,7 @@ exports.rcmp = function rcmp(a, b) {
  * @returns {Number}
  */
 
-exports.double256 = function double256(target) {
+common.double256 = function double256(target) {
   var n = 0;
   var hi, lo;
 
@@ -113,12 +114,48 @@ exports.double256 = function double256(target) {
  * @returns {Number}
  */
 
-exports.getDifficulty = function getDifficulty(target) {
-  var d = DIFF_TARGET;
-  var n = exports.double256(target);
+common.getDifficulty = function getDifficulty(target) {
+  var d = DIFF;
+  var n = common.double256(target);
+
   if (n === 0)
     return d;
+
   if (n > d)
     return d;
+
   return Math.floor(d / n);
 };
+
+/**
+ * Get target from bits as a uint256le.
+ * @param {Number} bits
+ * @returns {Buffer}
+ */
+
+common.getTarget = function getTarget(bits) {
+  var target = consensus.fromCompact(bits);
+
+  if (target.isNeg())
+    throw new Error('Target is negative.');
+
+  if (target.cmpn(0) === 0)
+    throw new Error('Target is zero.');
+
+  return target.toArrayLike(Buffer, 'le', 32);
+};
+
+/**
+ * Get bits from target.
+ * @param {Buffer} data
+ * @returns {Buffer}
+ */
+
+common.getBits = function getBits(data) {
+  var target = new BN(data, 'le');
+
+  if (target.cmpn(0) === 0)
+    throw new Error('Target is zero.');
+
+  return consensus.toCompact(target);
+};
diff --git a/lib/mining/miner.js b/lib/mining/miner.js
index 9a666701..a4c9e8a6 100644
--- a/lib/mining/miner.js
+++ b/lib/mining/miner.js
@@ -138,7 +138,7 @@ Miner.prototype._createBlock = co(function* createBlock(tip, address) {
     address: address,
     coinbaseFlags: this.options.coinbaseFlags,
     witness: this.chain.state.hasWitness(),
-    halvingInterval: this.network.halvingInterval,
+    interval: this.network.halvingInterval,
     weight: this.options.reservedWeight,
     sigops: this.options.reservedSigops
   });
@@ -146,11 +146,12 @@ Miner.prototype._createBlock = co(function* createBlock(tip, address) {
   this.assemble(attempt);
 
   this.logger.debug(
-    'Created miner block (height=%d, weight=%d, fees=%d, txs=%s).',
+    'Created block template (height=%d, weight=%d, fees=%d, txs=%s, diff=%d).',
     attempt.height,
     attempt.weight,
     Amount.btc(attempt.fees),
-    attempt.items.length + 1);
+    attempt.items.length + 1,
+    attempt.getDifficulty());
 
   if (this.options.preverify) {
     block = attempt.toBlock();
diff --git a/lib/mining/template.js b/lib/mining/template.js
index 2b5e410d..611f2a2b 100644
--- a/lib/mining/template.js
+++ b/lib/mining/template.js
@@ -35,27 +35,127 @@ function BlockTemplate(options) {
   if (!(this instanceof BlockTemplate))
     return new BlockTemplate(options);
 
-  this.prevBlock = options.prevBlock;
-  this.version = options.version;
-  this.height = options.height;
-  this.ts = options.ts;
-  this.bits = options.bits;
-  this.target = consensus.fromCompact(this.bits).toArrayLike(Buffer, 'le', 32);
-  this.locktime = options.locktime;
-  this.flags = options.flags;
-  this.coinbaseFlags = options.coinbaseFlags;
-  this.witness = options.witness;
-  this.address = options.address;
-  this.sigops = options.sigops;
-  this.weight = options.weight;
-  this.reward = consensus.getReward(this.height, options.halvingInterval);
+  this.prevBlock = encoding.NULL_HASH;
+  this.version = 1;
+  this.height = 0;
+  this.ts = 0;
+  this.bits = 0;
+  this.target = encoding.ZERO_HASH;
+  this.locktime = 0;
+  this.flags = 0;
+  this.coinbaseFlags = DUMMY;
+  this.witness = false;
+  this.address = new Address();
+  this.sigops = 400;
+  this.weight = 4000;
+  this.interval = 210000;
+  this.fees = 0;
   this.tree = new MerkleTree();
   this.left = DUMMY;
   this.right = DUMMY;
-  this.fees = 0;
   this.items = [];
+
+  if (options)
+    this.fromOptions(options);
 }
 
+/**
+ * Inject properties from options.
+ * @private
+ * @param {Object} options
+ * @returns {BlockTemplate}
+ */
+
+BlockTemplate.prototype.fromOptions = function fromOptions(options) {
+  assert(options);
+
+  if (options.prevBlock != null) {
+    assert(typeof options.prevBlock === 'string');
+    this.prevBlock = options.prevBlock;
+  }
+
+  if (options.version != null) {
+    assert(typeof options.version === 'number');
+    this.version = options.version;
+  }
+
+  if (options.height != null) {
+    assert(typeof options.height === 'number');
+    this.height = options.height;
+  }
+
+  if (options.ts != null) {
+    assert(typeof options.ts === 'number');
+    this.ts = options.ts;
+  }
+
+  if (options.bits != null)
+    this.setBits(options.bits);
+
+  if (options.target != null)
+    this.setTarget(options.target);
+
+  if (options.locktime != null) {
+    assert(typeof options.locktime === 'number');
+    this.locktime = options.locktime;
+  }
+
+  if (options.flags != null) {
+    assert(typeof options.flags === 'number');
+    this.flags = options.flags;
+  }
+
+  if (options.coinbaseFlags != null) {
+    assert(Buffer.isBuffer(options.coinbaseFlags));
+    this.coinbaseFlags = options.coinbaseFlags;
+  }
+
+  if (options.witness != null) {
+    assert(typeof options.witness === 'boolean');
+    this.witness = options.witness;
+  }
+
+  if (options.address != null)
+    this.address.fromOptions(options.address);
+
+  if (options.sigops != null) {
+    assert(typeof options.sigops === 'number');
+    this.sigops = options.sigops;
+  }
+
+  if (options.weight != null) {
+    assert(typeof options.weight === 'number');
+    this.weight = options.weight;
+  }
+
+  if (options.interval != null) {
+    assert(typeof options.interval === 'number');
+    this.interval = options.interval;
+  }
+
+  if (options.fees != null) {
+    assert(typeof options.fees === 'number');
+    this.fees = options.fees;
+  }
+
+  if (options.items != null) {
+    assert(Array.isArray(options.items));
+    this.items = options.items;
+  }
+
+  return this;
+};
+
+/**
+ * Instantiate block template from options.
+ * @param {Object} options
+ * @returns {BlockTemplate}
+ */
+
+BlockTemplate.fromOptions = function fromOptions(options) {
+  return new BlockTemplate().fromOptions(options);
+};
+
 /**
  * Create witness commitment hash.
  * @returns {Buffer}
@@ -82,13 +182,36 @@ BlockTemplate.prototype.getWitnessHash = function getWitnessHash() {
   return crypto.hash256(data);
 };
 
+/**
+ * Set the target (bits).
+ * @param {Number} bits
+ */
+
+BlockTemplate.prototype.setBits = function setBits(bits) {
+  assert(typeof bits === 'number');
+  this.bits = bits;
+  this.target = common.getTarget(bits);
+};
+
+/**
+ * Set the target (uint256le).
+ * @param {Buffer} target
+ */
+
+BlockTemplate.prototype.setTarget = function setTarget(target) {
+  assert(Buffer.isBuffer(target));
+  this.bits = common.getBits(target);
+  this.target = target;
+};
+
 /**
  * Calculate the block reward.
  * @returns {Amount}
  */
 
 BlockTemplate.prototype.getReward = function getReward() {
-  return this.reward + this.fees;
+  var reward = consensus.getReward(this.height, this.interval);
+  return reward + this.fees;
 };
 
 /**
diff --git a/test/chain-test.js b/test/chain-test.js
index 4e2afe08..4b70dc87 100644
--- a/test/chain-test.js
+++ b/test/chain-test.js
@@ -707,7 +707,7 @@ describe('Chain', function() {
   it('should fail to connect bad amount', co(function* () {
     var job = yield cpu.createJob();
 
-    job.attempt.reward += 1;
+    job.attempt.fees += 1;
     job.refresh();
     assert.equal(yield mineBlock(job), 'bad-cb-amount');
   }));