How to show 10 items with a dynamic list, randomly selected, from a collection with over 100 items?

[rcm (Ryan McSweeney)]

So, I have well over 100 items in a collection.
Is it possible to limit the number of items shown in a dynamic list (randomly selected), to let’s say 10 items, without limiting the list to the first 100 items in the collection?

So let’s say there’s a pool of 500 items in a collection, 10 of those will be shown at one time, however, it would be possible for any of those 500 items to be selected.

If a person were to refresh the page enough times they would eventually see all the collection items.

[rcm (Ryan McSweeney)]

I also just noticed that sort order works differently than I thought. It seems once a page is published dynamic items will stay in the same order despite using random sort order. The random sort order produces an order before publishing.
Discovered this by refreshing a page several times and saw no order change.

[samliew (samliew.com)]

The random sort order produces an order before publishing.

Random is refreshed every 12 hours. If you want realtime random, you have to display all items in the dynamic list, then use custom JavaScript code to remove all except the random few.