Does a Hard Fork always result in a new coin?


#1

No, most Hard Forks are just “required” upgrades and having nothing to do with new coins.

Despite the impression that many people have from the coin-forking “craze” period of 2017, most Hard Forks do not result in new coins.

What’s a Hard Fork, then?

Simply put, a Hard Fork is when some important underlying code is changed, and everyone must upgrade in order to avoid being left behind. It’s required because the new version can’t work with the old version - it’s incompatible. In most cases, everyone wants the upgrade, so everyone updates their software in advance of the fork time and everything keeps running.

Accidents

There’s always a possibility that a few people don’t get around to upgrading, or forget. After the fork time comes, their software probably just won’t work, because it’s no longer compatible with what everyone else is running. They’re stuck until they update their software.

In theory, it’s possible that a few miners, and a few pools, and a few exchanges all fail up to update their software. If they happen to be connected to each other then, as a group, they may naturally form a functioning system on the “old version” while everyone else is up and running on the “new version” - but that’s super unlikely to happen “by chance” if the fork is a planned and desired upgrade.

(Even if it does happen by chance, those people will probably notice that they’re stranded soon enough, and upgrade to get “in sync” with everyone else.)

Disputes

Sometimes, though, an upgrade is very contentious, and a lot of people don’t want the new version. That’s what happened with Ethereum; some people chose not to update their software and kept running the old version; we now call their coin Ethereum Classic, and the rest of that community runs Ethereum.

Intentional

The last case is when a code change is intended to bring about new coin via Hard Fork. These aren’t accidents or the result of disagreements - they are clearly and intentionally designed to start up a new coin, and they don’t succeed unless unless a working ecosystem of people decide to run all the necessary software. There were a lot of high-profile examples of this in 2017, and although they got a lot of press, they are not “normal” for a Hard Fork upgrade.

Normal

The normal Hard Fork upgrade process looks like this:

  1. Let’s say we’re at block 200,000 now. Some important improvements require a Hard Fork to roll out.
  2. Code is developed and made public; this code works the old way until block 210,000, and works the new way after that.
  3. Pretty much everyone updates to the new code.
  4. Block 210,000 comes around, and everything keeps on working. The new improvements are running.
  5. A few people realize their systems aren’t working because they didn’t update; Oops! They go and update their code and join the rest of the world.

No new coins.


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