These are a few suggestions for rules for the Blackstone Fortresses' "mega-death" weapons. They are all powerful, but not unbalancing in a game. You should get you opponent's permission before you use any of the below suggestions.
(This is a version that is not as powerful as the fluff, though it IS powerful.)
When firing, you nominate your target, and the weapon will get a number of to-hit dice (Strength) equal to the number of hits the target ship has. When you have two Blackstone Fortresses combining their power together, the weapon will hit any ship, regardless of armour, on a 4+, and for every point of damage done you will roll a second dice and it will do a critical hit on a 5+. When you combine 3+ Blackstone Fortresses, everything will be as above, but the weapon will only need a 3+ to hit. This will give a very powerful weapon, but not one that will totally destroy game balance.
I would limit the range on this weapon to no more than 45cm and possibly even 30cm.
(Warning: This weapon is extremely powerful!)
Here's a rather simple notion for the Megadeath weapon. It takes its mechanics roughly from Babylon Project's Earth Force Sourcebook (Jon Tuffley).
Each activated Blackstone Fortress can generate a pool of Mega Death Energy (MDE) and has a capacitor to store MDE. In fact, each such fortress can generate 1 to 3 points of MDE each turn (D6: 1 is 1 point, 2-5 is 2 points, 6 is 3 points). The capacitor of a single Blackstone Fortress can hold 6 points of MDE.
To discharge the MDE, a target is nominated and the distance measured in lengths of 15 cms and fractions thereof. Eg. 10 cm is one range band, 31 to 45 cms is third range band.
Roll a number of dice equal to the MDE in the capacitor. From each die, subtract the number of range bands to the target. Sum the remaining pips; this is the damage done. Count the number of 6's rolled. Roll that many dice again, and again subtract the number of range bands. Add to the damage total. Repeat as long as 6 's are rolled. The capacitor's charge is reduced to 0.
Planets are destroyed by a single shot doing 20 damage or multiple shots totalling 40 damage. Suns are destroyed by shots doing 50 damage.
Two Blackstone Fortresses may cooperate to build a single large attack. The space between them is filled with arcing, corruscating energy. The space between the fortresses increases the total capacity by 6 MDE, for a potential total of 18 MDE. With more Fortresses, the total MDE becomes truly staggering.
| # Fortresses | Total MDE |
| 2 | 2x6 + 6 or 18 |
| 3 | 3x6 + 3x6 or 36 |
| 4 | 4x6 + 6x6 or 60 |
| 5 | 5x6 + 10x6 or 90 |
| 6 | 6x6 + 15x6 or 126 |
The tradeoffs:
A crippled Blackstone Fortress may not generate or store MDE. If crippled with MDE in the capacitor, the Blackstone Fortress takes damage equal to 2x the MDE in the battery.
If multiple Blackstone Fortresses are cooperating and one is crippled, the crippled Blackstone Fortress immediately takes 2x its fraction of the MDE. (Eg. One of three Blackstone Fortresses is crippled while the three hold 21 points of MDE. Its share is 1/3 of 21 or 7 MDE, so it takes 14 damage.). If the remaining MDE is within the capacity of the reduced group, then it is held by them. Any excess beyond the reduced capacity causes 1X excess MDE to each and every Blackstone Fortress.
If an object enters the space between cooperating Blackstone Fortresses, it absorbs the full MDE charge and drains the capacitor. It automatically takes 2x MDE damage. If this exceeds its remaining hits, the excess damage is spread evenly between the cooperating Blackstone Fortresses. (Eg. A brave Imperial cruiser with 8 hits remaining dives between two Blackstone Fortresses with 13 MDE stored. The cruiser would take 26 damage, but can only take 8 hits. The remaining 18 damage is split evenly between the two Fortresses, 9 hits apiece).
To fire the super-mega-death-cannon you must nominate a target ship and guess the range to it. The range that can be guessed is between 30cm and 450cm. Then place the nova cannon template so that it's outer edge is at the range guessed. If the central hole of the template is over the base of any ship, friend or foe, that ship suffers 3D6 hits reguardless of its Armour value. If the outer portion of the template touches a ship's base it suffers three automatic hits. If no ships were hit by the mega-death-cannon place three blast markers under the center of the template. Hits from a super-mega-death-cannon ignore shields. Due to the large amount of time it takes for the Blackstone to recharge the cannon it may only be fired once per game.