Necklace of Fireballs: This device appears to be nothing but beads on a string, sometimes with the ends tied together to form a necklace. (It does not count as an item worn around the neck for the purpose of determining which of a character’s worn magic items is effective.) If a character holds it, however, all can see the strand as it really is—a golden chain from which hang a number of golden spheres. The spheres are detachable by the wearer (and only by the wearer), who can easily hurl one of them up to 70 feet. When a sphere arrives at the end of its trajectory, it detonates as a fireball spell (Reflex DC 14 half ).
Spheres come in different strengths, ranging from those that deal 2d6 points of fire damage to those that deal 10d6. The market price of a sphere is 150 gp for each die of damage it deals.
Each necklace of fireballs contains a combination of spheres of various strengths. Some traditional combinations, designated types I through VII, are detailed below.
Type I: 3d6 x 2; 5d6 x1
Type II: 2d6 x2; 4d6 x2; 6d6 x1
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Type VII: 3d6 x2; 5d6 x2; 7d6 x2; 9d6 x2; 10d6 x1
If the necklace is being worn or carried by a character who fails her saving throw against a magical fire attack, the item must make a saving throw as well (with a save bonus of +7). If the necklace fails to save, all its remaining spheres detonate simultaneously, often with regrettable consequences for the wearer.
Moderate evocation; CL 10th; Craft Wondrous Item, fireball.
Unless you want to make a specific rule, I'm fairly certain that a command word must be spoken clearly and firmly, not just murmured.palleomortis said:These bracers seem to be completely ordinary until the wearer murmer the command word. At wich point the arm braces glows whith an incredable light. When the light receads, there is a longsword +2 in the weilders dominant hand, and a small sheild in the other. This action take a full round, as would drawing a sword, and they recead once the weilder murmers the command word once again.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.