Name:  Autocannon/20 (Prototype)
Type (Category):  Weapon (Ballistic)
Reference:  Interstellar Operations: Alternate Eras (p. 112)

Description:
Today’s standard autocannon (identified as AC in shorthand) is functionally identical to the models used as far back as the days of the Terran Alliance. Designed to cope with improvements in armor technologies of the day, these weapons maintained their destructive edge through more than 800 years of battlefield evolution. Even so, their time was nearing its end when the newer Ultra and LB-X autocannon classes emerged. In fact, among the Clans these weapons have apparently ceased to exist (their last shots reportedly fired in the early 3050s, when they were mounted on machines largely regarded as refit museum pieces). Only their relatively inexpensive design, and the advent of specialized munitions usable by these weapons alone, has prevented the likes of Armstrong’s J11, Mydron models A through D, SarLon’s MaxiCannon and the Luxor Devastator-20 from becoming the next forgotten relics of history.

Game Rules:
Autocannons may not be fired if the unit is shut down or if its pilot/crew is otherwise prevented from acting, but loaded or partially loaded AC ammo bins are always live and will explode per standard rules if critically hit during game play.

Primitive prototype ballistic weapons (standard autocannons and the Long Tom artillery weapon) will suffer a jam on any to-hit roll result of 2 and may carry only three-quarters of their listed ammunition capacity (rounding up) per ton. Jammed weapons cannot be cleared in battle, and are considered damaged—but not destroyed—for game play and repair purposes.

Regardless of their nature, all Primitive prototype basic weapons are incompatible with modern targeting enhancers, including Artemis, Narc, and the targeting computer.

BattleMechsIndustrialMechsCombat Vehicles

Prototype Date:	2488
Production Date:	—
Extinction Date:	2510
Recovery Date:	—

BattleMech Specific Construction Rules

WEAPONS AND EQUIPMENT COMBAT AND CONSTRUCTION TABLE
RULES LEVEL PROGRESSION TABLE
AMMUNITION COMBAT AND CONSTRUCTION TABLE
ALPHA STRIKE WEAPON CONVERSION TABLE
Special Unit Abilities

MegaMek Output → Weapon List:  AC/20p
MegaMek Output → Critical Slot:  Autocannon/20 Primitive
Record Sheet Output → Critical Slot:  Autocannon/20 (Prototype)

Prototype Date:	2488
Production Date:	—
Extinction Date:	2510
Recovery Date:	—

IndustrialMech Specific Construction Rules

WEAPONS AND EQUIPMENT COMBAT AND CONSTRUCTION TABLE
RULES LEVEL PROGRESSION TABLE
AMMUNITION COMBAT AND CONSTRUCTION TABLE
ALPHA STRIKE WEAPON CONVERSION TABLE
Special Unit Abilities

MegaMek Output → Weapon List:  AC/20p
MegaMek Output → Critical Slot:  Autocannon/20 Primitive
Record Sheet Output → Critical Slot:  Autocannon/20 (Prototype)

Prototype Date:	2488
Production Date:	—
Extinction Date:	2510
Recovery Date:	—

Combat Vehicle Specific Construction Rules

WEAPONS AND EQUIPMENT COMBAT AND CONSTRUCTION TABLE
RULES LEVEL PROGRESSION TABLE
AMMUNITION COMBAT AND CONSTRUCTION TABLE
ALPHA STRIKE WEAPON CONVERSION TABLE
Special Unit Abilities

MegaMek Output → Weapon List:  AC/20p
MegaMek Output → Critical Slot:  Autocannon/20 Primitive
Record Sheet Output → Critical Slot:  Autocannon/20 (Prototype)