I've actually houseruled my own Batman style Grapnel Gun.
The Grapnel Gun is the size of a heavy pistol and uses shotgun shells to launch a length of cable 20 meters long at a selected target. Once attached, the internal battery retracts the cable at high speed, either propelling the user to the target, or bringing the target to the user. Against an unfixed opponent, treat this as an opposed Knockdown Test. If the defender's Physical Limit is lower than the Strength + net hits of the Attacker, he is pulled off his feet and dragged to the attacker at the rate of retraction. Otherwise, the attacker must succeed in a Body + Strength test or have the grapnel yanked out of his hands. Even if he succeeds, he is instead pulled off his feet and dragged towards the defender. If the rate of retraction is fast enough to incur falling damage, this applies to both the defender and the attacker as the two collide. The Grapnel Gun holds 10 charges and regains 1 charge per ten seconds when plugged in. The Grapnel can be retracted at various speeds. Switching between these speeds requires a Change Device Mode Simple Action.
Steady: The Grapnel is retracted at a speed of 3 meters per combat turn, fast enough to clear a 1 story building quickly but safely. The Grapnel needs at least 1 charge to retract at this speed, but can be used indefinitely. This requires a minimum Strength of 2 to hold onto the gun. If the user lacks sufficient strength, they must make a Strength + Body test, with a threshold equal to the difference between their Strength Attribute and the requirement for the rate of retraction, or else have the gun pulled out of their hand.
Slow: The Grapnel is retracted at a speed of 5 meters per combat turn. This expends 1 charge, and requires a minimum Strength of 3 to hold onto the gun.
Fast: The Grapnel is retracted at a speed of 10 meters per combat turn. This expends 2 charges, and moves the target at high enough speed that they must resist falling damage as if they fell 5 meters. This requires a minimum Strength of 4 to hold onto the gun.
Turbo: The Grapnel instantly retracts the full length of its cable, moving at a speed of 20 meters per combat turn. This uses up 5 charges, and causes 10 meters worth of falling damage on impact due to the high speed of retraction. A minimum Strength of 6 is required to hold onto the gun..
Wireless: Laser range finders, ultrasound and weight sensors between the gun and the head of the cable are able to quickly calculate the exact distance being traversed and the full load being pulled, allowing the Grapnel to calibrate its retraction speed to slow to a safe stop. No falling damage is taken, no matter how fast the grapnel is retracted. In addition, changing retraction speeds requires only a Free Action, and it recharges through induction at a rate of 1 charge per hour.
Grapnel Gun
Accuracy: 4
Damage: 7P
AP: -1
Mode: SS
RC: -
Ammo: 5 (m)
Avail: 12R
Cost: 1000 nuyen
Optional Heads:
Electromagnetic Head: This Grapnel head is designed to latch onto any ferrous metal, such as the bodies of vehicles or heavy girders. When activated, any metal target, or target that contains metal, receives a -4 penalty to its defense roll to avoid the Grapnel. When properly attached, the rope will break before the magnet fails. Turning the Magnet on or off requires a Change Device Mode Simple Action.
Wireless: The magnet can be activated and deactivated as a Free Action.
Damage Modifier: -
AP Modifier: -
Avail: 4
Cost: 100 nuyen
Gecko Head: This Grapnel Head has a large sphere of amorphous Gecko pad material the size of a softball. On impact, it flattens against the target, dramatically increasing its surface area and holding fast. The Gecko Head can stick to almost any surface and support the weight of a full grown Troll without slipping, but it becomes worthless when wet and can't stick to surfaces coated against adhesives. Once stuck, removing the Gecko Head requires a Complex Action to carefully peel it off its target, or a Simple Action if liquid can be poured over it.
Wireless: The adhesive in the Gecko Pad can be temporarily disabled with a Wireless Signal, allowing it to be removed as a Free Action.
Damage Modifier: -2S
AP Modifier: +1
Avail: 12
Cost: 500 nuyen
Spike Head: This Grapnel Head is a hardened, diamond tipped spike, designed to pierce through a target before deploying barbs to hold it fast. The Spike can pierce any barrier up to Structure Rating 12 and deals 1 box of damage to the barrier. Against living targets, it becomes lodged in their armor if the damage is converted to stun, or gets embedded in their body if it deals Physical. Removing the spike once its lodged into a target requires a Complex Action and a Strength + Body (4) test. Pulling the spike out like this deals two boxes of damage to Structures, or base weapon damage to a living target that took Physical damage from the initial attack. Alternatively, it can be removed without additional damage using a First Aid + Logic (2) [Mental] test.
Wireless: The internal barbs can be retracted with a wireless signal, allowing the spike to easily slip out of whatever hole it made. If lodged into a living target, this still requires a Complex Action.
Damage Modifier: -
AP Modifier: -4
Avail: 12F
Cost: 120 nuyen
