Lucky charm
"Lucky charms"[1] are the life-gaining artifacts in Alpha, Crystal Rod, Iron Star, Ivory Cup, Throne of Bone, and Wooden Sphere, and their derivatives in other sets and expansions. The original so-called "lucky charms" were printed in every Core Set through 8th Edition. The art for each card from 5th Edition to 8th (save 7th Edition which was commissioned art by different artists) was illustrated by Donato Giancola.
The original "lucky charm" for white read:
Whenever a player plays a white spell, you may pay
. If you do, you gain 1 life.
Rulings
These rulings do apply to every version of Lucky charms.
- The ability triggers whenever any player, not just you, casts a spell of the appropriate color.
- If a player casts a spell of the appropriate color, the artifact's ability triggers and is put on the stack on top of that spell. The artifact's ability will resolve (causing you to gain 1 life) before the spell does.
Antiquities "lucky charm"
A life-gaining artifact following the theme of the original "lucky charms", Urza's Chalice, was printed in Antiquities. As of Magic 2014, it is the only "lucky charm" to be released as a common rather than an uncommon.
Darksteel "lucky charms"
Another cycle of life-gaining artifacts, improved versions of the "lucky charms" — Angel's Feather, Demon's Horn, Dragon's Claw, Kraken's Eye, and Wurm's Tooth — were printed in Darksteel, and they have been reprinted in every core set through Magic 2012. Each of these cards was illustrated by Alan Pollack.
The version from Darksteel reads:
Whenever a player plays a white spell, you may gain 1 life.
The newer versions require no activation cost, but are cost more.
Scars of Mirrodin "lucky charm"
Following the theme set in Darksteel, Scars of Mirrodin improved on the original artifact "lucky charm" that was printed in Antiquities. Golem's Heart used the same change as the Darksteel "lucky charms" did, taking out the activation cost, but making it cost more like the Darksteel cycle above.
This card was illustrated by Matt Cavotta.
Magic 2014 Staves
For Magic 2014, a cycle of uncommon artifacts costing 
was introduced, more than the Darksteel cycle and 
more than the original cycle. Each of them allowed a player to gain 1 life both when casting a spell of the color, or when playing a certain type of basic land. The cycle consists of Staff of the Sun Magus (White/Plains), Staff of the Mind Magus (Blue/Island), Staff of the Death Magus (Black/Swamp), Staff of the Flame Magus (Red/Mountain) and Staff of the Wild Magus (Green/Forest). All five were illustrated by Daniel Ljunggren