What does it take to change the protocol?

[IveBeenBit]

I know from time to time, some people will say 21 million is not enough coins and that we will need more. I strongly disagree.

But, just saying, what would it take to change the protocol so that mining will produce more than 21 million? Would it take 100% agreement among all nodes? 51% agreement?

Similarly, what if one day 7 decimal places is not enough and something like 10- or 11- decimal precision is required? Would it be just as difficult?

I ask because whenever someone brings up raising the 21 million cap, the unanimous answer among the knowledgeable is, "It ain't going to happen."

But they seem to think that increasing the decimal places is relatively trivial if that's needed.

Can anyone explain the difference?

[pe1pip]

I know from time to time, some people will say 21 million is not enough coins and that we will need more. I strongly disagree.

But, just saying, what would it take to change the protocol so that mining will produce more than 21 million? Would it take 100% agreement among all nodes? 51% agreement?

Similarly, what if one day 7 decimal places is not enough and something like 10- or 11- decimal precision is required? Would it be just as difficult?

I ask because whenever someone brings up raising the 21 million cap, the unanimous answer among the knowledgeable is, "It ain't going to happen."

But they seem to think that increasing the decimal places is relatively trivial if that's needed.

Can anyone explain the difference?

by increasing the number of decimals you'll not cause inflation like you would when just printing more bitcoins. Printing more money is a tried and tested way of causing (hyper-)inflation.

[DeathAndTaxes]

You can't change the protocol.  Period.  All you can do is fork it. 

If a single person past, present, or future doesn't like the fork they can continue to run the "current" Bitcoin.  Yeah the "new fork" may become more popular and eventually most people may think of "Bitcoin" as the new fork but the original/current fork will always exist.  For this reason controversial changes like changing the minting rate, maximum number of coins, irreversibility of transactions, etc are almost certainly never going to happen.

For example say today a large fraction of the Bitcoin community felt that the block reward was too low and they modified the protocol to support a 100 BTC block reward.  Current users/clients would see these blocks as invalid.  Period.   They aren't "Bitcoin".  Now those who supported it could VOLNTARILY choose to upgrade to the client which supports the fork but many would choose not to.  Some miners would move to the "higher profit" fork but that would mean more profits for the miners who stayed.   Both camps could call their protocol "Bitcoin" but they would be incompatible with each other.   Most likely the fork would simply die off and be forgotten.  IF both forks were heavily supported (and both called "Bitcoin") it likely would be mutually assured destruction as the confusion and chaos would undermine both forks.  For this reason many users will never support ANY controversial hard fork for any reason.  The danger/damage is simply too high.