When was the 200 rep per day limit added?

Question

It's common knowledge that Stack Exchange has a reputation cap preventing users from earning more than 200 reputation points in a day.

Has the daily reputation limit always been a part of Stack Exchange? If not, when was the cap added?

Answer 1

This is pretty straightforward to find out.

Stack Overflow was publicly launched on September 15, 2008 (source: a quick google search).

The first version of the rep FAQ contains a mention of the point cap dated September 24, 2008 (source: look at the revision history).

Even earlier than that, there is a reference to it in beta from August 29, 2008.

So yes it's been around the whole time since the public launch, and at least partially through beta.

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Another source of info for these types of things is the search, sorted by time. For example, as early as November, 2008 there were references to the cap (source: the last page of a quick search for "reputation cap" sorted by date).

Answer 2

This post from October 2008 says:

...the current "200 reputation points per day through voting" limit

So it existed a very short time after Stack Overflow was publicly launched. As for the public beta before that, no idea...

There's also a feature request to get rid of the limit from 2009.

So the answer is either "always", or "very shortly after launch".