A sprue, as everyone who has ever done any gaming miniature work knows, is the extra bits of metal or plastic that connect all of the moulded pieces and is used during the moulding to get the molten material into the moulds. The sprue is usually cut away and neatly trimmed before mounting and painting the miniature. Sprue is very useful for modellers, as it often resembles pipes or other bits of industrial miscellanea, and can itself be cut up and stuck together to make very convincing scenery pieces.

We would be seriously negligent if we didn't inform you of the extremely useful sprue equation, courtesy of Wikipedia's article:

Transcript

GM: The droid army's heavy weapons can't penetrate the Gungan force field.
R2-D2: Awesome.
Jar Jar: Yay! Now wesa just has to wait for da geysers.
GM: Droid troop carriers arrive and start disgorging thousands of combat droids.
Jar Jar: Thissa not so good.
R2-D2: That's... a lot of minis. Want a hand separating them from the sprues?
GM: No, they're marching in formation.
{droids start walking through the bubble wall}
[SFX]: {droid army chanting} We are badass through and through!
[SFX]: {droid army chanting} Now it's time to take Naboo!
GM: By the way, the force field design you gave me didn't include the "low velocity impacts" enhancement.
R2-D2: Nobody ever needs that!
{droids begin firing}
Captain Tarpals: Hold da line!
Jar Jar: Protect da shield generators!
[SFX]: {droid army chanting} We are tougher than the Hutts!
[SFX]: {droid army chanting} We will kick these Gungans' butts!
R2-D2: And it would have put the dinosaur ponies over their encumbrance limit!
Obi-Wan: Great saving throw versus admitting you screwed up.