Electromagnetic Pulse Weapons

Weapon/Defence Archive: Weapons: EMP

[Blinder Missile] -[EMP Mine] -[EMP Missiles] -[Ion Cannon–Type 1] -[Ion Cannon–Type 2] -[Ion Pulse Cannon] -[Ion Pulse Weapon] -[Neutralizer] -[Plasma Torpedo] -[Powerleech Missiles] -[Scrambler Pulse] -[Temporal Distortion Gun]


When these were discussed, as Weapon of the Week No. 2, they caused a lot of controversy, as I remember, the views largely split into two camps:

The first was those that felt EMP weapons that inflicted blanket thresholds, like the EMP missile in More Thrust provided an 'equaliser' against the larger ships.

The second felt that all weapons of the same cost (MASS and points) should have roughly equivalent effects, and thus disliked weapons that inflicted blanket thresholds as the effect could vary widely depending upon the size of the target ship.

No consensus was reached between the two camps.

A further development is the publishing on the list of a proposed update to the 'MT' missile system, including a new set of rules for EMP missiles. These new EMP missiles have their effects and costs balanced so that they are just about cost-effective when used against the largest of the ships in the fleet books. Should these missiles become standard in a future Fleet Book or edition of Full Thrust, then they could be considered a 'baseline' for EMP weapons.


[Alan Brain] (GZG-L)

This weapon is described in the Missiles section.


[Paul Wellman] (Samuel Penn's Website)

This weapon is described in the Minelayers section.


[Paul Wellman] (Samuel Penn's Website)

EMP MT Missiles and EMP salvo missiles are described in the Missiles section.


[Dean Gundberg] (Star Ranger's Crossover Web Page) WotW #2

For Range 0-10mu roll 2D6, while for range 10-20mu roll 1D6. These dice are scored as beam dice, i.e. rolls of 4 or 5 inflict 1 "hit", while rolls of 6 inflict 2 "hits".

Each "hit" is not marked off the damage track but instead is the number of threshold rolls the target ship must perform. All Ion Cannon hits from a firing ship are resolved one ship at a time. The threshold roll number is the same as the target ship's next threshold level.

Threshold rolls are made for the following systems in this order:

  1. Screens
  2. Special Electronics (Sensors, ECM, etc.)
  3. Fire Controls
  4. FTL Drive
  5. Main Drive
  6. (Back to top of list)

Mass and cost same as Class 2 Beam with the same arcs.

ICONS (examples):    3-arc Ion Cannon  (3 arc)     6-arc Ion Cannon  (6 arc)     3-arc Ion Cannon  (alternative 3 arc)      6-arc Ion Cannon  (alternative 6 arc)


[WotW #2]This weapon was discussed as part of WotW #2, however, no consensus was reached.


[Pat Shephard] ( Full Thrust New Systems Index.)

The firing of Ion Cannons is handled the same as beam batteries, and "hits" are calculated the same as beams (1-3 no hits, 4-5 1 hit, 6 2 hits). Armour and screens do not reduce "hits". However, these "hits" do not mark off damage boxes but instead are the potential number of systems destroyed by threshold rolls caused by the Ion Cannon hit.

Once the potential number of systems destroyed is determined (and assuming it is greater than zero), the defender chooses a system and rolls a 5-6 threshold check on that system. He then chooses another system and rolls another 5-6 threshold check on that system. This continues until all systems have been rolled for, or until the total number of systems destroyed equals the number of "hits" rolled by the Ion Cannon. If a second ship hits the target ship with Ion Cannon fire, a new set of threshold rolls would commence. Bio-ships and similar ships without internal systems would take damage equal to the hits rolled due to shock damage.

Ion Cannons may fire through only one arc.

Combined, MASS, points cost, and Range table.

Ion Cannon Type MASS Point Cost Range
0–10mu 10–20mu 20–30mu
Light 3 5 2D6 1D6
Heavy 4 8 3D6 2D6 1D6

ICON:   Light Ion Cannon   (Light)     Heavy Ion Cannon   (Heavy)


[Charles]This weapon is similar to the other Ion Cannon, except that it relies on the defending player choosing which systems to roll threshold checks for, rather than a 'shopping list'. It may well be worth standardising the range bands and points cost.


[Brendan Robertson] (GZG List 2-12-01)WotW #2

The Ion Pulse Cannon is described in the Spinal Mount weapons section.


[Brendan Robertson] (GZG List 2-12-01)WotW #2

The Ion Pulse Weapon is a weapon capable of temporarily disabling systems on a target ship using a powerful pulse of ions.

Roll dice as for a beam battery [same number of dice as class of weapon; -1 per 12mu out].
The roll equals the maximum number of systems that can be damaged by this Ion Pulse Weapon attack. On a single die, a roll of 4+ on an unscreened ship will add 1 to the total. A roll of 6 will add 2 to the total (and roll again). Screens/Shrouds/etc. effect the roll as they would a beam weapon (i.e. level 1 screen would cause rolls of 4 to be ignored; level 2 screens would ignore 4s and 6s would only add 1 to the total instead of 2).

Roll a threshold check until the number of system potentially damaged are damage by the Ion Pulse Weapon attack or every system has been checked under this attack. Threshold checks should be done in the following order:

  1. Screens/Shields/Cloaking Fields/Shrouds
  2. Fire Controls
  3. Sensors/ECM (if using MT Sensors & ECM)
  4. Engines
  5. Weapons starting with the most mass and going to the least mass
  6. Bays/Hangers/Passenger spaces
  7. Core (if 2nd hull row has no undamaged hull boxes).

As with a Wave Gun, a ship may not be screened in the arc through which it fires a IPW (but other arcs may be screened).
Stealing the idea from Noam:
The Ion Pulse Weapon may be fired in PDS mode with a range of 6mu by de-focusing the pulse. Any fighters in the arc of effect may not attack this round and loose 1 point of endurance. Missiles/Pods/Plasma are effected the same as if a number of PDS equal to the class of the Ion Pulse Weapon had fired at them (in the case of pods, assuming they would be affected by PDS anyway).
The Ion Pulse Weapon may not be used with an ADFC. Ships (friend or foe) caught in the unfocused Ion Pulse Weapon attack suffer effect as if hit by a Class-1 Ion Pulse Weapon. A fire control must be dedicated to the task in order to allow an Ion Pulse Weapon to fire in PDS mode, and may not be used for other purposes this turn.
Obviously, if an Ion Pulse Weapon fires in PDS mode, it may NOT fire in standard mode in the same turn.

The Ion Pulse Weapon can only have a single fire arc.

The Ion Pulse Weapon has the same MASS as a beam battery of one class larger (thus a class 3 Ion Pulse Weapon would have the same MASS as a class 4 beam battery, namely 8 MASS). It has a cost of 3 points per MASS.

ICON:    Ion Pulse Weapon


[WotW #2]This weapon was discussed as part of WotW #2, however, no consensus was reached.
[Charles]To me, this weapon has certain similarities with Dean Grundberg's Ion Cannon in that both systems affect a number of systems based upon the roll of beam dice, and both systems have a specific order in which the affected systems make their threshold checks. However, there are differences, the Ion Cannon only comes in 1 class, has 3 or 6 arcs, and ignores screens, while the Ion Pulse Weapon is available in multiple classes, is mitigated by screens, and has a special PDS mode. I recommend that at least we attempt to unify the mechanics to a certain degree (i.e. both systems use the same 'pick list', should we decide to retain that mechanic), and, possibly, combine them into a single weapon system.


[Charles Taylor] (GZG-L) (updated 17-Feb-2002)

This weapon was named an Effector Beam in earlier versions of the archive, and was placed in the beams section.

The Neutralizer Beam is a highly sophisticated weapon that disables the target systems of an enemy ship by disrupting their control circuits.

Each Neutralizer Beam can target a single system on an enemy ship, this requires that one fire control be dedicated to the task of targeting that system. Should multiple Neutralizer Beams be targeting that ship, then one fire control is required for each target system (c.f. needle beams). For each effector, roll 1d6, and subtract the level of screens protecting the target, if the result is 4 or more, then the system is disabled. Disabled systems can be re-activated by repairing them, in the same way that systems knocked out by a failed threshold check can.

Optionally, the Neutralizer Beam can be allowed to target core systems, in which case it can disable a core system on a roll of 6 regardless of the screen level of the target. The targeted Core System should then roll a threshold check with a bonus equal to the ships screen level, but not the usual core system bonus (thus a ship that is on its second row of hull boxes and has level 1 screens would succeed on a roll of 6). If this option is used, the costs listed may need increasing.

The range of a Neutralizer Beam Beam is 12mu per class, however, the effect is the same at all ranges.

A class 1 Neutralizer Beam Beam may also be used in a point defence role, in exactly the same way that Phalon Pulsers can.

The MASS requirement and points cost of an Neutralizer Beam of a given class is listed in the following table:

Class MASS Points cost
1 (3-arc) 1 12 points
1 (6-arc) 2 24 points
2 (1-arc) 2 24 points
2 (3-arc) 3 36 points
2 (6-arc) 4 48 points
3 4 + 1 per extra arc 12x MASS

Each further increase in class is double the MASS of the previous class, the cost is always 10× the MASS.

ICONS (examples):    3-arc Class 2 Neutralizer  (Class 2, 3 arc)     1-arc Class 3 Neutralizer  (Class 3, 1 arc)


[Aaron Teske] (Spacefleet conversion page)

This weapon is described in the Genre section.


[Noam Izenberg]WotW #2

This weapon is described in the Missiles section.


[Noam Izenberg] WotW #2

The Scrambler Pulse uses an intense energy pulse to cause ship-wide system incapacitation on the target ship.

The Scrambler Pulse has a range of 18mu, and affects the target ship as if it had been struck by an EMP missile (see More Thrust, page 3 for details).
In addition, a Scrambler Pulse can target Missiles and Fighters in intercept mode as if it were a PDS, within 6mu. The EMP backwash on the firing ship when attacking targets (including fighters or missiles) within 6mu can have a detrimental effect, roll 1d6, on a roll of 5 or 6, the firing ship must make a threshold check at 6.

The Scrambler Pulse has a MASS of 4, +1 per additional arc (maximum of 3 arcs). It costs 3 points per MASS.

ICONS:     1-arc Scambler Pulse  (1 arc)     2-arc Scambler Pulse   (2 arc)     3-arc Scambler Pulse  (3 arc)
(Alternatives):     1-arc Scambler Pulse  (1 arc)     2-arc Scambler Pulse   (2 arc)    3-arc Scambler Pulse   (3 arc)


[WotW #2]This weapon was discussed as part of WotW #2, however, no consensus was reached.
[Oerjan] Another possibility for a "standard" EMP gun, instead of using one of the various Ion Cannon mechanics. Because the pulse does not have the aiming problems of a missile, the effect will be reduced to either:

  1. FD-6 on attack. Roll of 4 = threshold at 6, 5= threshold at 5+, 6=threshold at 4+
  2. As MT missile but 3-4 = threshold on 6+, 5-6=threshold on 5+
Most other advantages of a direct fire EMP weapon are mitigated by the limited range. One other possible fix is making extra arcs +2 Mass.
[Charles] Since the new EMP missile details were published, I'd base it on those; if it is treated as a MT EMP missile that has a range of 18mu and automatically hits (then rolls to see if the EMP has any effect), then its MASS should be doubled.


[Noam Izenberg] WotW #2

This weapon is found in the Weapons: Other section.

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Last Update May 31, 2002, NRI