Lithium Fusion Engine (Mecha-Press)

Description

Originating in Mecha-Press magazine, the Lithium Fusion Engine is much like a hybrid car, taking a smaller engine and pairing it with a network of Lithium Fusion batteries to store surplus energy that the 'Mech is not using and release it on demand.

Construction and Gameplay Rules

Though the network of Lithium Fusion batteries occupy up to 14 critical slots (some can be integrated into the engine using the same rules as heat sinks), they add negligible mass. As a result, to find the tonnage of the engine, before calculating the engine rating as normal, reduce the Desired Walk MP by 1. This is only for construction purposes.

For example, a 60 ton mech (such as the Prodigal Son) using a Lithium Fusion Engine with a Walk MP of 6 would only need a 300-rated Lithium Fusion Engine, instead of a 360-rated Standard Fusion Engine.

Lithium Fusion Engines cannot be combined with other Fusion Engine types, such as XL fusion engines, XXL fusion engines, Large Engines, Primitive engines, and compact engines. They also may not be combined with Fission Engines, Fuel Cells or Internal Combustion Engines.

Every destroyed battery will produce 1 point of heat for the next turn. If five or more batteries are destroyed, reduce the mech's Walk MP by 1, recalculating the Run MP and maximum Jump MP as normal.

Legality

As a noncanon item, Lithium Fusion Engines are not under any circumstances Tournament Legal, and if they were to appear under Total Warfare rules, would most likely be classified as Experimental Technology.

In the original publication, they are marked as Level 3 technology.

Balance Concerns

Disclaimer: None of the statements in this subsection come from a published source. This write-up is included solely for the purpose of demonstrating the engine's effect on game balance as tonnage increases.

In lighter mechs, Lithium Fusion Engines do not provide as much of a benefit as an XL Engine, and thus could be considered the poor man's answer, but as a mech increases in weight the benefits of using a Lithium Fusion Engine increase dramatically.

Using the formula provided above (shared again here: Tonnage x (Desired Walk MP – 1)) to determine engine rating, an Atlas could carry a 200-rated Lithium Fusion Engine instead of a 300-rated standard fusion to go at the same speed as before (not only benefiting from a lighter engine, but a lighter gyro as well), or could carry a 300-rated Lithium Fusion to gain the same performance as a 400-rated standard engine.

Furthermore, it becomes possible for 'Mechs to achieve equivalent performance to engine ratings equal to or greater than 405, with a hypothetical 375 Lithium Fusion in a 75-ton 'Mech providing a 450 standard fusion engine’s level of performance, or a 400 engine in a 100-ton 'Mech providing a 500 standard engine's performance (keep in mind that even the 500 XXL still weighs over 160 tons).

This equation breaks down when used on a superheavy 'Mech (which can be forgiven, as superheavy 'Mechs didn't even exist when these rules were published), with an engine of equal rating to the 'Mech's tonnage allowing it to move as fast as an UrbanMech, and at the same time having the mass of the superheavy Gyro from 8 tons to 4. If you chose to use a 400-rated Lithium Fusion Engine in a 200-ton 'Mech, though, you would get the equivalent of a 600 engine worth of performance (3/5 movement on a superheavy), an engine rating that doesn't even exist under any current version of official rules.

On the other end of the scale, with sufficiently light 'Mechs, the weight savings or increase in performance provided by using a Lithium Fusion Engine are insufficient to justify the increase in bulk or the risk of losing those performance benefits to a lucky critical hit, and thus it really does just become a cheaper and crappier version of the XL Engine.