FIFTY
HAPPY
GIGAS
The 4x5 matrix above has a certain peculiar feature, which allows you to perform a certain card trick. Although it serves ok as a mnemonic for this trick, it is not a nicely structured sentence, like "NEVER TRUST BLIND DATES" (better, but misses the needed feature).
I ask you to find the essential feature, and then to suggest a nice mnemonic, logically making sense.
badly needed
