Lucky Strike
Lucky Lucky (ラックアップ Rakku Appu , lit. "Luck Up"), also translated as Lucky Strike in Kingdom Hearts, is an ability which appears in Kingdom Hearts and Kingdom Hearts II. In both games, it increases the drop rate of items, and this effect can be increased by equipping multiple copies of the ability. In Kingdom Hearts, "Lucky Strike" requires 3 AP to equip, while in Kingdom Hearts II, it requires 5 AP.
In Kingdom Hearts II, there are a maximum of seven Lucky Lucky's that can be equipped (the four belonging to the Sweet Memories, Meteor Staff, Genji Shield, and Lucky Ring, and the three belonging to the party characters). As the Lucky Lucky abilities stack exponentially, this results in an enemy's base drop rates being multiplied by 627.5%.
In Kingdom Hearts II Final Mix, Lucky Rings can in fact be synthesized, and in "Critical Mode", Roxas starts with two additional Lucky Lucky. However, Lucky Lucky was removed from the weapons which previously contained it, so only seven additional Lucky Lucky can be equipped, for a total of fourteen. Furthermore, the boosts from Lucky Lucky stack linearly instead of exponentially, so this results in a drop rate increase of only 800%. As compensation for this, Sora has an additional Lucky Lucky in Limit Form, which can raise the drop rate increase to 850%.
Learning Lucky Lucky
In Kingdom Hearts, Sora learns "Lucky Strike" at level 15 with the Dream Shield, 39 with the Dream Rod, or 69 with the Dream Sword. Donald Duck learns it at level 55 and Goofy learns it at level 27. Aladdin, Ariel, and Peter Pan have "Lucky Strike" as a default ability.
In Kingdom Hearts Final Mix, Sora learns "Lucky Strike" at level 24 with the Dream Shield, 48 with the Dream Rod, or 90 with the Dream Sword. Donald Duck learns it at level 44 and Goofy learns it at level 24. Aladdin, Ariel, and Peter Pan have "Lucky Strike" as a default ability.
In Kingdom Hearts II, Sora learns "Lucky Lucky" at level 41 with the Dream Sword, 53 with the "Dream Shield", and 99 with the Dream Rod. Donald Duck learns it after defeating the Nobodies at The Old Mansion. Goofy learns it after defeating Shenzi, Banzai, and Ed at The King's Den. Jack Sparrow and Jack Skellington have "Lucky Lucky" as a default ability. Finally, the Sweet Memories, Meteor Staff, Genji Shield, and Lucky Ring have Lucky Lucky as their Equipment Ability.
In Kingdom Hearts II Final Mix, Sora learns "Lucky Lucky" by raising Limit Form to level 6. Donald Duck learns it after defeating the Nobodies at The Old Mansion. Goofy learns it after defeating Shenzi, Banzai, and Ed at The King's Den. Limit Form, Jack Sparrow, and Jack Skellington have "Lucky Lucky" as a default ability. Roxas has two "Lucky Lucky" as a default ability in Critical Mode. Finally, the Lucky Ring has Lucky Lucky as its Equipment Ability.