Continuing my trend of ripping off other media and throwing it into D&D, let's take a quick look at the various applications of throwing hooks at things.
So, for those of you not acquainted with the show, let me simply say that it's about grappling hook ninja kids in a medieval army that kills giants by using crazy grappling hook maneuvers. I love the anime myself, and I soon found myself wanting to throw grappling hooks at people in D&D.
Now that that's over with, what are the elements it needs? Well, it's similar to flight, so it should use the fly skill. However, it can't quite work with the flight rules because of the fact that it, well, can't make you fly. Second, it needs to work with weapons, as per the anime. Here, we'll be letting it work with several weapons. Third, it needs to allow players to use inertia.
General stats:
Feat: 3 dimensional maneuver gear training
Prerequisites: Dex 15, exotic weapon proficiency (3d maneuver gear)
Description: As a soldier, you trained in specific and odd weaponry, a strange contraption said to be a flying miracle machine by some and a mad man's intriguing suicide method by others.
Effect: Allows proficiency in flight using maneuver gear. Otherwise, all checks made are at a -8 penalty, Fly is now treated as a class skill.
Feat: Soldier's flyby
Prerequisites: Dex 15, 3d maneuver gear training, fly 4 ranks
Description: Your stupidity and bravado developed weird aerial strategies and maneuvers, often allowing you to fight much more efficiently than your comrades.
Benefit: Controlling the maneuver gear during flight is now a move action, and can attack anything in your you pass by as a standard action (you may not make full attacks).
Feat: Improved soldier's flyby
Prerequisites: Dex 16, 3d maneuver gear training, fly 6 ranks, Soldier's flyby
When they mocked you for your stupidity, you trained and refined your techniques, and came out better than anyone.
Benefit: Controlling your flight is now a free action.
3 dimensional maneuver gear
Exotic Weapon, light armor
Weight total: 50 pounds on a full tank, see advanced mechanics.
Basic description: Allows players to grapple on to walls and materials with a hardness lower than ten, at a range of 200 feet. Using the weapon is a standard or move equivalent action (player's choice at time). Controlling it during flight is always a full round action. The item includes three pieces: The gas release, and the grappling hooks, and the weapon control.
Advanced mechanics:
Grappling hook: The hook and rope is what makes this thing tick. By firing grappling hooks with immense force powered by compressed gas, the hook will safely lodge into anything with a hardness less than 10. The ropes are 200 feet long, and six sets of rope and grapples are stored in the mechanisms (total for the device). The grapples and ropes weight about 10 pounds on their own, and the grapples are similar to a crossbow bolt. However, due to their size and design, an attack made using the gear is at a -2 penalty and deals 1d4 damage.
Gas release: The Gas release is a small fan and pulley in the back, used to pull a user on the hooks or improve maneuverability. You can, in the same action as your attacks are made, pull yourself to your hook's destination at 50 feet per round. Each 50 feet traveled releases .25 units of gas, and a full tank includes 10 units of gas. The release nozzle can be used to improve maneuverability by one step or increase speed in the direction you're facing by 10 feet/second. This costs .1 units of gas per round to sustain. Reloading the gas canisters takes one hour of pumping and does not fatigue you. Reloading the mechanism with a full canister takes 2 rounds.
Weapon control: The weapon you control the gear with must be specially fitted to the gear itself. You use controls on the weapons to activate the pieces in your gear, and the weapon is attached to the rest of the gear. You can be disarmed, but picking the weapon up is a swift action that does not provoke attacks of opportunity. Only several weapons may be fitted. They include:
Longsword
Light shield
Short sword
Rapier
Scimitar
Light mace
Light and Heavy Crossbow (including repeating)
Control During cabled flight: You may maneuver yourself with some proficiency whilst hurtling at a wall by shifting your weight as a move action. You may displace yourself in any direction up to ten feet with a DC 18 fly check. By using two cables, you add a +2 circumstance bonus to this check. Your destination remains the same. You can pull a cable in as a standard action.
Releasing the cables prior to landing: You can choose to release the grappling hook before you land by disengaging the hooks. This is a swift action. If you do this, you are now in free fall and have little control over your landing location. You will still fly in the same direction of your rope and cannot turn. You may displace yourself five feet per round with a successful DC 20 fly check. You then obey falling rules.
Landing: Landing requires a DC 10 tumble check to not take damage if you are travelling horizontally. Damage is 3d6/50 feet. If you fall, you take damage as normal.
Criticism is more than welcomed, hopefully this is fun for someone.