The first run boxes of Rise of the Duelist (the ones with the special mark on the box) will each contain 1 “+1 Bonus Pack”, the contents are as follows

-It will contain 1 random card from a list of 19
-The list contains 1 Prismatic Secret Rare only card, 8 Ultra Rare cards, and 10 Super Rare cards
-The Ultra and Super Rares have Prismatic Secret Rare versions as well
-The Ultra and Super Rares are the same ones as the ones from Rise of the Duelist
-The Prismatic Secret Rare only card is a Prismatic Secret Rare version of a card that currently exists
-The pack will not be included in re-runs of the set

Source:https://yu-gi-oh.jp/index.php?page=details&&id=756