|Description||Double the damage Mario takes.|
|Mario/Partner||Only Mario can use it|
There are very few strategically valid reasons to use this badge. The probable intended use of this badge is to partner it with the Return Postage badge creating a situation in which most enemies do significant damage to themselves as well as Mario.
A secondary use of this badge, in which is it temporarily used, is to use its function to quickly and intentionally reduce Mario's HP to below 5 (placing Mario in "danger") and then de-equip the Double Pain badge. Doing so would ensure that the various Close Call family of badges are made active reliably.
A third usage is an example of emergent gameplay that is entirely player preference. This function is to intentionally increase the difficulty of the game -- essentially functioning as a "Hard Mode" for players who are so inclined as to take such a challenge. To use it this way, players seek out the Double Pain badge as quickly as possible, equip it immediately upon purchase, and never remove it.