It's a batching mechanic that checks for three creatures each with at least one creature type, "Warrior, Wizard, and Rogue." Once you have all three, it will give you a special bonus
Like most Magic: The Gathering cards, the value of Ghostly Prison depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Secret Lair Drop)
The whole plot involving Old Toby, and the discovery of trade between Saruman and the Shire, always caught my attention
Top 3 Red Common/Uncommons: Boltwave: One mana, 3 damage to each opponent
Merry, Warden of Isengard + Pippin, Warden of Isengard I kind of like the go-wide stuff happening with the Merry, Warden of Isengard and Pippin, Warden of Isengard version of the Food and Fellowship Commander precon, but neither really convinces me
Back in my day, we played Phyrexian Negator and liked it