I'm rather unhappy with the current performance table in the MGT book... I really don't like its general asymmetry and how some hulls have a large gap in drive performance. e.g. in the existing rules an 1800dt ship basically can get drives at J (perf 1), M (perf 2), Q (perf 3), T (perf 4), and then it leaps to Z (perf 5) and then presumably to bigger engines for perf 6. What's up with that big leap from T to Z? And why should such a ship not get any advantage from using drives between U and Y, or between K and L?
So I came up with a new performance table, which fits with a Cunning Plan I have too (see later). Note that the intent of this table is just to get something that I'm happier with, and is not remotely concerned with compatibility with existing designs or OTU canon. I've shared it with some folks already, but here it is for everyone to use:
You'll notice it starts at 100dt with the 2/4/6 progression, then 200 is 1/2/3/4/5/6, then 300 is 1/1/2/2/3/3/4/4/5/5/6/6 (two of each number) and then everything after that is 1/1/1/2/2/2/3/3/3/4/4/4/5/5/5/6/6/6 (three of each number). This means we don't have ships that have 4-6 rows taken up by the same type of drive.
It also means that we can actually offer some kind of improvement with the higher drive letters. What I was thinking was something like this:
The first row that a performance number shows up is the basic drive. It works exactly as described in the book.
The second row that a performance number shows up is the "XL" version of the drive. It works exactly as decribed in the book, but because it's bigger and has built-in redundancies and backups, it can absorb a free hit in combat with no extra bad effects (the drive effectively has 4 'hit points' instead of three).
The third row that a performance number shows up is the "GTX" version of the drive - think of this as the souped-up turbo version
. Not only does it still have the one extra hit point (it doesn't get a second one), but it also has a special effect that can be used.
Now this does mean that a drive with a given letter isn't actually the same drive across all ship sizes any more. In the original rules a class-F power plant would be identical in ships from 200dt to 1200dt (with decreasing performance as the volume increases) - that's not true anymore here. With this alternate table it'd be a basic 6-drive for a 200dt ship, a basic 3-drive for a 300dt ship, an XL 2-drive for a 400dt ship, a basic 2-drive for a 500dt ship, a GTX 1-drive for a 600dt and 700dt ship, and an XL 1-drive for an 800dt and 900dt ship. This being the case, there's no real point in actually referring to them as drive letters at all.
Instead, we could just refer to the basic drive as "a", the XL drive as "b" and the GTX as "c", and add those after their performance ratings. So for example a basic 2-drive could be called a 2a-drive, and an XL 4-drive could be a 4b-drive, and a GTX 3-drive could be called a 3c-drive. Thus we can do away with drive letters completely.
GTX drives
The GTX "special effects" depend on the drive type:
Jump Drives: The drive is so well designed and uses fuel so efficiently that when determining the fuel used per jump, it treats the jump number as one less than it actually is (a J1 is treated as 0.5). A 2c J-drive on a 600dt ship would therefore use 60 tons of fuel for a J2, not 120. A 5c J-drive on an 1800dt ship would use 720 tons of fuel for a J5 instead of 900 tons of fuel. (i.e. subract 10% of the ship's hull size from the fuel tonnage per jump).
Manoeuvre Drives: The ship can go into Overdrive - it can acccelerate at a rating of G+1 (even above 6G) for a short period of time, but with the risk of a blowout after the Overdrive ends (avoided on a special Recovery roll). Note that Basic and XL drives can also go into Overdrive, but the difficulties of both the Overdrive and Recovery rolls are increased by one level for XL drives and by two levels (relative to GTX) for Basic drives.
To go into Overdrive: Intelligence, Engineering roll (Difficult -2), 1-6 minutes (1 starship combat round). See below for consequences.
Recovery roll: Intelligence, Engineering roll (Average), 1-6 minutes (1 starship combat round). Any failure generates a combat hit on the drive, any success avoids this.
Overdrive roll:
Exceptional Failure: The ship does not enter Overdrive. Recovery roll automatically fails - panels have shorted out, pipes have cracked/exploded, etc.
Average Failure: The ship does not enter Overdrive. Recovery roll must still be made, at Difficult (-2)
Marginal Failure: The ship can accelerate at its G-rating+1 for (Engineering skill) starship combat rounds, but the difficulty of the Recovery roll is Difficult (-2).
Marginal Success: The ship can accelerate at its G-rating+1 for (1+Engineering skill) starship combat rounds. Recovery roll made at Average difficulty.
Average Success: The ship can accelerate at its G-rating+1 for (2+Engineering skill) starship combat rounds. Recovery roll made at Average difficulty.
Exceptional Success: The ship can accelerate at its G-rating+1 for (2+Engineering skill) starship combat rounds, Recovery roll automatically succeeds.
Power Plants: Power Plants have to be the same performance and same type as the highest rated drive in the ship. So if there's a 2a-Manoeuvre, and a 2b-Jump, the power plant has to be at least a 2b-Plant.
I'm not actually sure what the "special effect" for Power Plants could be here though. I can't find any mention of power allocation for weapons or systems, or any description of what excess power does (it used to give you extra Agility, but I couldn't find that in the corebook either). Without that, it's a lot harder to figure out a way to give a power plant a special beneficial ability here.
Thoughts, constructive comments, glaring oversights, obvious flaws etc? Remember again that this is not intended to fit with OTU assumptions - it's an entirely different set of assumptions.
So I came up with a new performance table, which fits with a Cunning Plan I have too (see later). Note that the intent of this table is just to get something that I'm happier with, and is not remotely concerned with compatibility with existing designs or OTU canon. I've shared it with some folks already, but here it is for everyone to use:
Code:
1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 (tonnage/100)
A 2 1 - - - - - - - - - - - - -
B 4 2 1 1 - - - - - - - - - - -
C 6 3 1 1 1 - - - - - - - - - -
D - 4 2 1 1 1 1 - - - - - - - -
E - 5 2 2 1 1 1 1 - - - - - - -
F - 6 3 2 2 1 1 1 1 1 - - - - -
G - - 3 2 2 2 2 1 1 1 1 - - - -
H - - 4 3 2 2 2 2 1 1 1 1 - - -
J - - 4 3 3 2 2 2 2 2 1 1 1 - -
K - - 5 3 3 3 3 2 2 2 2 1 1 1 -
L - - 5 4 3 3 3 3 2 2 2 2 1 1 1
M - - 6 4 4 3 3 3 3 3 2 2 2 1 1
N - - 6 4 4 4 4 3 3 3 3 2 2 2 1
P - - - 5 4 4 4 4 3 3 3 3 2 2 2
Q - - - 5 5 4 4 4 4 4 3 3 3 2 2
R - - - 5 5 5 5 4 4 4 4 3 3 3 2
S - - - 6 5 5 5 5 4 4 4 4 3 3 3
T - - - 6 6 5 5 5 5 5 4 4 4 3 3
U - - - 6 6 6 6 5 5 5 5 4 4 4 3
V - - - - 6 6 6 6 5 5 5 5 4 4 4
W - - - - - 6 6 6 6 6 5 5 5 4 4
X - - - - - - - 6 6 6 6 5 5 5 4
Y - - - - - - - - 6 6 6 6 5 5 5
Z - - - - - - - - - - 6 6 6 5 5
You'll notice it starts at 100dt with the 2/4/6 progression, then 200 is 1/2/3/4/5/6, then 300 is 1/1/2/2/3/3/4/4/5/5/6/6 (two of each number) and then everything after that is 1/1/1/2/2/2/3/3/3/4/4/4/5/5/5/6/6/6 (three of each number). This means we don't have ships that have 4-6 rows taken up by the same type of drive.
It also means that we can actually offer some kind of improvement with the higher drive letters. What I was thinking was something like this:
The first row that a performance number shows up is the basic drive. It works exactly as described in the book.
The second row that a performance number shows up is the "XL" version of the drive. It works exactly as decribed in the book, but because it's bigger and has built-in redundancies and backups, it can absorb a free hit in combat with no extra bad effects (the drive effectively has 4 'hit points' instead of three).
The third row that a performance number shows up is the "GTX" version of the drive - think of this as the souped-up turbo version

Now this does mean that a drive with a given letter isn't actually the same drive across all ship sizes any more. In the original rules a class-F power plant would be identical in ships from 200dt to 1200dt (with decreasing performance as the volume increases) - that's not true anymore here. With this alternate table it'd be a basic 6-drive for a 200dt ship, a basic 3-drive for a 300dt ship, an XL 2-drive for a 400dt ship, a basic 2-drive for a 500dt ship, a GTX 1-drive for a 600dt and 700dt ship, and an XL 1-drive for an 800dt and 900dt ship. This being the case, there's no real point in actually referring to them as drive letters at all.
Instead, we could just refer to the basic drive as "a", the XL drive as "b" and the GTX as "c", and add those after their performance ratings. So for example a basic 2-drive could be called a 2a-drive, and an XL 4-drive could be a 4b-drive, and a GTX 3-drive could be called a 3c-drive. Thus we can do away with drive letters completely.
GTX drives
The GTX "special effects" depend on the drive type:
Jump Drives: The drive is so well designed and uses fuel so efficiently that when determining the fuel used per jump, it treats the jump number as one less than it actually is (a J1 is treated as 0.5). A 2c J-drive on a 600dt ship would therefore use 60 tons of fuel for a J2, not 120. A 5c J-drive on an 1800dt ship would use 720 tons of fuel for a J5 instead of 900 tons of fuel. (i.e. subract 10% of the ship's hull size from the fuel tonnage per jump).
Manoeuvre Drives: The ship can go into Overdrive - it can acccelerate at a rating of G+1 (even above 6G) for a short period of time, but with the risk of a blowout after the Overdrive ends (avoided on a special Recovery roll). Note that Basic and XL drives can also go into Overdrive, but the difficulties of both the Overdrive and Recovery rolls are increased by one level for XL drives and by two levels (relative to GTX) for Basic drives.
To go into Overdrive: Intelligence, Engineering roll (Difficult -2), 1-6 minutes (1 starship combat round). See below for consequences.
Recovery roll: Intelligence, Engineering roll (Average), 1-6 minutes (1 starship combat round). Any failure generates a combat hit on the drive, any success avoids this.
Overdrive roll:
Exceptional Failure: The ship does not enter Overdrive. Recovery roll automatically fails - panels have shorted out, pipes have cracked/exploded, etc.
Average Failure: The ship does not enter Overdrive. Recovery roll must still be made, at Difficult (-2)
Marginal Failure: The ship can accelerate at its G-rating+1 for (Engineering skill) starship combat rounds, but the difficulty of the Recovery roll is Difficult (-2).
Marginal Success: The ship can accelerate at its G-rating+1 for (1+Engineering skill) starship combat rounds. Recovery roll made at Average difficulty.
Average Success: The ship can accelerate at its G-rating+1 for (2+Engineering skill) starship combat rounds. Recovery roll made at Average difficulty.
Exceptional Success: The ship can accelerate at its G-rating+1 for (2+Engineering skill) starship combat rounds, Recovery roll automatically succeeds.
Power Plants: Power Plants have to be the same performance and same type as the highest rated drive in the ship. So if there's a 2a-Manoeuvre, and a 2b-Jump, the power plant has to be at least a 2b-Plant.
I'm not actually sure what the "special effect" for Power Plants could be here though. I can't find any mention of power allocation for weapons or systems, or any description of what excess power does (it used to give you extra Agility, but I couldn't find that in the corebook either). Without that, it's a lot harder to figure out a way to give a power plant a special beneficial ability here.
Thoughts, constructive comments, glaring oversights, obvious flaws etc? Remember again that this is not intended to fit with OTU assumptions - it's an entirely different set of assumptions.