Can a block be created without the reward transaction?

[micaman]

When a miner creates a valid block to add to the blockchain, does the miner include the reward transaction in the block himself?
Can a block without a reward transaction be considered valid and added to the blockchain?
Thanks

[DeathAndTaxes]

The "reward" txn is the coinbase txn (no relationship with the company having the same name).   There must be one and only one coinbase txn in every block. A block with no coinbase txn is always invalid.  A miner can however elect to take less or none of the reward (i.e. a coinbase txn with an output of 0).  There is no good reason to do so but it can be done.

[micaman]

So if a miner is willing to take no reward for his effort, he will generate blocks with 0 reward, therefore maintaining the total amount of unmined bitcoin further away.
As the subsidy is cut in half every 210,000 blocks, wouldn't this be able to cause an early halving?

[DeathAndTaxes]

So if a miner is willing to take no reward for his effort, he will generate blocks with 0 reward, therefore maintaining the total amount of unmined bitcoin further away.
As the subsidy is cut in half every 210,000 blocks, wouldn't this be able to cause an early halving?

It won't cause an early halving, the halving is based on blocks not coins. The halving will always occur exactly every 210,000 blocks. Any coins which can but are not taken as a reward are permanently lost. This has happened to a couple hundred BTC already although it is probably due to bugs in early mining software not some intentional act.

[coinsolidation]

Also the maximum number of halvings is hard coded, so once that number has passed that, the reward is set to 0.

[micaman]

Imagine the first 210.000 bitcoin blocks were created without claiming its reward, would that have destroyed 50 x 210.000 bitcoin?

[DannyHamilton]

Also the maximum number of halvings is hard coded, so once that number has passed that, the reward is set to 0.

The block reward is the sum of the block subsidy and all the transaction fees from all the transactions included in the block.

Therefore, once the block subsidy reaches 0.00000000 BTC, the reward will be only the transaction fees.

Imagine the first 210.000 bitcoin blocks were created without claiming its reward, would that have destroyed 50 x 210.000 bitcoin?

Yes.

[coinsolidation]

Also the maximum number of halvings is hard coded, so once that number has passed that, the reward is set to 0.

The block reward is the sum of the block subsidy and all the transaction fees from all the transactions included in the block.

Therefore, once the block subsidy reaches 0.00000000 BTC, the reward will be only the transaction fees.

Yes, we should be careful with our use of terms. I meant to refer to the following code:

if (halvings >= 64) return nFees;

[indiguy]

Imagine the first 210.000 bitcoin blocks were created without claiming its reward, would that have destroyed 50 x 210.000 bitcoin?

What a waste. so its not exactly 21million coins?

[DannyHamilton]

Imagine the first 210.000 bitcoin blocks were created without claiming its reward, would that have destroyed 50 x 210.000 bitcoin?

What a waste. so its not exactly 21million coins?

It was never "exactly 21 million coins".  People round up to 21 million because it is easier to say that there "will never be more than 21 million" than it is to say the protocol is programmed for a maximum of "twenty million nine hundred ninty-nine thousand nine hundred ninty-nine and nine thousand seven hundred sixty-nine ten thousandths" bitcoins.


Now it just happens to be less than that, not that it matters since far more than what has been lost to mining errors has been lost to lost private keys.

[DeathAndTaxes]

Imagine the first 210.000 bitcoin blocks were created without claiming its reward, would that have destroyed 50 x 210.000 bitcoin?

What a waste. so its not exactly 21million coins?

It never was exactly 21M BTC.  It was not more than 21M BTC.  Even if all rewards were claimed and the genesis block was spendable the total money supply would have been 20,999,999.97690000 it is now slightly less than that (not even 0.01%) 21M BTC is a lot easier to explain though.  Still cheer up. You own a slightly larger percentage of the coin supply than you thought you did.

[DannyHamilton]

D&T, you're getting slow.

 

[micaman]

So each one worths even more! 
Thanks a lot for the explanation