GURPSよろず

Rapid Fire with Thrown Weapons
A classic tactic of ninja and gadgeteers is to toss many tiny throwing weapons (caltrops, ball bearings, shuriken, etc.) at once, with the goal of hitting somebody with something. This is far less precise than Rapid Strike with Thrown Weapons (see above). Use the following special rules instead.
The weapons used must be ready for throwing. It takes a turn to ready a fistful of tiny weapons from a handy container, or to ready the container itself. You can toss up to BL/50 lbs. of small, sharp items or BL/20 lbs. of small, blunt ones with one hand (use BL/20 lbs. for all weapons in a cinematic campaign!), or launch up to BL/2 lbs. of projectiles from a container – box, pouch, hollow staff, etc. This is a limit on the number of items you can throw for useful effect, not a measure of how many you can lift.
Treat the entire collection of thrown weapons as a missile weapon with Acc 0, RoF and Shots equal to the number of items hurled, and Rcl 2. For four shots or less, Damage is at -1 per die relative to a single weapon of that kind, and Range is 2/3 usual. For more than four shots, Damage is at -2 per die and range is 1/3 usual. Bulk is -2 for a fistful of weapons, -6 for any kind of container.
Handle the throw as a rapid-fire missile attack; see Rapid Fire (p. B373). Roll against Throwing to hit, regardless of what you’re throwing. You can throw all the weapons at one target for a bonus to hit or use Spraying Fire (p. B409) to attack multiple foes. All-Out Attack (Suppression Fire) isn’t an option – that assumes a steady stream of fire, not a single burst of projectiles.
If you know Throwing Art, you can roll against that skill to hit, and receive its usual bonuses to range and damage!

Example: A comic-book ninja with ST 13 and Throwing-14 hurls a handful of shuriken at a foe 2 yards away. His BL is 34, so he could normally toss 34/50 = 0.68 lb. of sharp objects with one hand . . . but this is a cinematic game, so he can toss a full 34/20 = 1.7 lbs. of shuriken. Since a shuriken weighs 0.1 lb., his “fistful” consists of 17 stars! For a ST 13 man, a shuriken normally has Damage 1d-1 cut, Range 6/13. Since there are more than four, this becomes Damage 1d-3 cut, Range 2/4. The attack has Acc 0, RoF 17, and Rcl 2. The bonus for RoF 17 is +4 and the range modifier for 2 yards is 0, so the ninja needs 14 + 4 = 18 to hit. He rolls a 10, succeeding by 8. That’s four multiples of Rcl 2, so he hits with one star plus four extras, for a total of five.