This ability is written Ripple X. When a spell with ripple is cast, its controller may reveal the top X cards of his or her library. If any of them have the same name as the spell with ripple that was cast, then he or she can cast those cards without paying their mana costs (this triggers their ripple abilities, so a player can ripple again). Any cards not thus cast are then put on the bottom of that player’s library. Ripple appears in Coldsnap, where all cards with the mechanic have ripple 4.
For this mechanic I am going to try and break away from my adventure/rpg bias. We have an RTS game in a setting populated by several neutral creatures. In this RTS we have a special type of unit called a herald. These units can call out to the nearby area and call neutral creatures of the same type to aid them in your battles. The downside is potentially alerting the enemy to your presence in the area. The Heralds would have a long cooldown for this ability and the range would grow as the herald grew more powerful.