Memory Aid--$2
Action
----
+$1
While this is in play, you may scrawl notes on your belly using your own blood.
This card turned morbid fast.
After playing Memory Aid, you may wish to play Band of Aids.
I expected to read "Band Aid"...
Edit: Or is that the same...? (non-native english speaker)
This is a joke that works on several levels. The instigating card, named "Memory Aid", references writing with one's own blood. This suggests that one is injured. When one is injured, an adhesive bandage may be applied to cover the wound. In many places (including Canada and the US), the brand name "Band-Aid" has become genericized for any such adhesive bandage. Thus, a Band-Aid could be used to cover the injury implied by the text of Memory Aid.
Here we come across the first point of humour -- both "Memory Aid" and "Band-Aid" have the word "Aid" in them. This similarity is not actually that funny, but people may find it amusing for some reason. It has the feeling of a pun, though it really isn't.
The actual humour comes from the twisting of the "Band-Aid" brand name into "Band
of Aids". The overall context of this joke is that this is a forum for the Dominion card game, and the "Memory Aid" card is a "bad card idea" posted therein. Note that Dominion has many cards in many expansions, one of which is "Band of Misfits" from the Dark Ages expansion. And thus we have our play on words -- "Band of Aids" is similar to "Band of Misfits". We have come full circle, and as we all know, circles are the funniest shape.