Weapons: EMP Projectors and Warheads

Version 1.5

“…then in ’59 the Luddites wiped the regional tax records with an EMP.”
EMP (electromagnetic pulse) weapons have been used by terrorists, saboteurs, activists and malicious pranksters. Criminals have used them to disable robots for later resale. As a consequence, most modern fifth and fourth-wave electronics are designed with some resistance to EMP attack. Military hardware of third-wave or higher has even greater resistance. Older equipment and that manufactured in the developing nations will probably be more vulnerable. Knock-off technology will vary in resistance, as it will in other qualities.
The smaller an item is, the less practical it becomes to effectively shield it.
Any equipment designed to receive radiowaves or similar transmissions will have some vulnerability, however. Radar or communications antennas are vulnerable. Power lines and some communication cables will act like antenna. EMP has no effect on optical devices and fibre-optic cables but may effect equipment they serve. Many military cybershells and vehicles only expose their antenna when using them. Firing an EMP weapon is often the initial move of a surprise attack. This has led to some military forces making more extensive use of laserphones and coded signal lights for communication.
Cyberswarms are very vulnerable to EMP weapons. Most use wireless recharging systems, so each microbot is a tiny receiver. Even when other power systems are used, microbots are too small to shield and rely on transmissions to co-ordinate. (THS 3e p.100:Counter-attacking cyberswams often involves defense swams or EMP munitions.”)
Holographic storage media such as cubes, wafers and holodiscs are not vulnerable to EMP. An EMP permanently erases software and data stored on magnetic media. Perhaps an extortionist with an EMP weapon will hold the millionaire’s antique VHS collection to ransom! 
An EMP attack affects anything electrical (or anyone with the Electrical disadvantage). Robots become unconscious, while total cyborgs suffer the Seizure incapacitating condition (4e p. B429), ignoring FP loss if they have the Machine metatrait. The GM should modify these effects accordingly. A critical hit, critical failure or a success by a margin of 10 or more will affect the effect. For resistant items the effect may be temporary, and the device be able to be brought back on line, possibly at limited capacity. Other systems may need extensive repairs or may be permanently disabled. In THS implants are relatively common and these may be affected by EMP attack. Repairs or replacement may require surgery or an equivalent medical procedure.
If no HT is given, assume a device has a HT of 10. The GM may rule a device has a lower of higher value. Hardening against EMP adds +3 to HT when resisting EMP attacks.

EMP Projectors

EMP projectors project ranged cone attacks (see Area and Spreading Attacks p. B413). Any target in the cone is struck by an affliction attack. This only afflicts electrical systems and those with the Electrical disadvantage. Make a HT roll or be shut down (or unconscious) for minutes equal to the margin of failure. Add +3 to resist beyond 1/2D range. The target’s SM adds to the HT roll to resist.
The statistics below are adapted from Ultra-Tech 4e p.121, where they are called “Microwave Disruptors”. Note that despite the names used in the table, EMP projectors do not have to look like guns. They may be built into innocuous items such as a briefcase or portable terminal. The scrambler is a pocket holdout device and will commonly be disguised as something else. For larger projectors, decide if a projector is small, medium or large and base it on the pistol, carbine or heavy EMP.
The heavy EMP projector can take the form of a tripod-mounted, crew-served weapon but is more usually used mounted on a vehicle or large cybershell. Weight given does not include the weight of the D cell (5lb) or the tripod (23lb). A mounted projector will use the vehicle or cybershell’s power supply. It may or may not have a D cell as auxiliary power.
Beam Weapons (Projector) (DX-4, or other Beam Weapons-4)
WeaponDamageAccRange (yards)Mass (lb)RoFShotsSTBulkRecoilCostLC
ScramblerHT-2 aff (1 yd)340/1200.3/B111(3)3-11$1202
EMP PistolHT-3 aff (1 yd)690/2701.8/C133(3)4-21$6503
EMP CarbineHT-4 aff (1 yd)12160/4805/2C128(3)5†-31$2,0002
Gunner (Beams) (DX-4, or other Gunner-4)
WeaponDamageAccRange (yards)Mass (lb)RoFShotsSTBulkRecoilCostLC
Heavy EMP ProjectorHT-8 aff (3 yd)18600/1,20070/D150(5)18M-81$32,0001

EMP Warheads

EMP warheads use explosive power or an energy cell to energize a non-nuclear electromagnetic pulse. Anything electrical (or anyone with the Electrical disadvantage) in the radius of the special effect (below) must make a HT-8 (2) resistance roll or be knocked out of action for seconds equal to the margin of failure. As for other EMP weapons, the GM can modify the effect accordingly to suit the vulnerability and nature of the affected item.
In THS, EMP warheads are not available in 15mm or smaller rounds, although perhaps someone to make a special custom item could be found. A round of less volume than a 12-gauge slug is very unlikely. Use 20-30mm for 30mm mini-missiles and 20mm projectiles. Use 40mm values for hand grenades and 40mm mini-missiles. The EMP hand grenade is bulkier and more complex than a THS-era explosive grenade, so weighs 1lb.
Grenades and satchel charges inflict the damage shown below. Missile and other projectiles replace their normal piercing damage with the damage shown below.
The explosive damage is for EMP warheads powered by an explosive power cartridge. Alternate models use an energy cell that is used to charge a capacitor. The capacitor is capable of being fully expended in a single use. These do no explosive damage, so are safer if the user needs an EMP against a nearby threat. Energy cell-powered EMP grenades are designed to be one use, but can sometimes be reused if the energy cell is replaced. For obvious reasons, capacitor grenades use non-rechargeable cells, so if rechargeable cells are used, twice as many, or a larger size will be needed. Some models use non-standard sizes of energy cell. Sometimes an expended capacitor grenade is beyond repair, however.
WarheadDamageExplosive Damage
18.5mm (12-gauge) HT-8 (2) spec. (1 yard) +1d-3 cr ex
20-30mmHT-8(2) spec(2 yard)+1d-2 cr ex
40mmHT-8(2) spec(4 yard)+1d cr ex
64mmHT-8(2) spec(8 yard)+2d cr ex
100mmHT-8(2) spec(16 yard)+4d cr ex

EMP Swatter

The EMP swatter is technically a projector, but resembles a non-explosive EMP warhead in operation and construction. Effectively it is an EMP warhead connected to an exterior power supply. Some models are also connected to a nearby C or D cell to permit limited operation in the event of power failure.
In high-security installations swatters are as common a sight as fire extinguishers or alarms. They are also found in conference rooms and anywhere else that cyberswarms and surveillance dust might be a concern.
An EMP swatter station includes a control to manually activate it. It may also be triggered remotely, from a control room or security office, or linked to cyberswarm detection systems. There may be slight delay before firing while a warning sounds so those with implants or sensitive equipment may get clear.
After firing a swatter will take several seconds (1d+3) for its capacitors to recharge. If used frequently (several times in a minute) there is a chance it will temporarily shut down or even burn out. During rapid use roll 3d for each firing after the first. It Malfunctions on 16 or higher.
THS Cities of the Edge (4e) p.8 has a section on EMP weaponry:

E-Weapons: Microwave disruptors (GURPS Ultra-Tech, p. 121) are “non-lethal” weapons that disrupt electronics and communications. These Ultra-Tech weapons can be assumed to exist in the Transhuman Space setting, although they may not be widespread; military cybershells and equipment will generally be sealed and shielded, making these things less than useful on the battlefield, and their only “civilian” uses would be for crime and sabotage. Getting hold of such a device may be an adventure in itself unless one happens to have contacts in the right kind of organization, a skilled technician-armorer for a friend, or some possibly illegal minifac templates. Nonetheless, they are practical weapons for striking against enemy infrastructure and communications, and China and the TSA used “E-weapons” in the Pacific War, causing high economic costs but few fatalities. Unfortunately, terrorists can also acquire them, and they tend to damage advanced nations more than poor nations. Hardening is easy for important equipment, but the real damage is the effect on the myriad ubiquitous, small civilian systems: doors, cybershells, clothing, virtual interfaces, v-tags, implants, cameras, lamps . . . Problems can easily cascade out of control. In a city, the effect on nearby traffic, businesses, tourists, and infrastructure can easily climb into stratospheric costs. Even optical systems typically have enough vital electronic parts to cause problems.