A question my group had that i thought about and while i have made a choice. I would like the forum members opinions / input on if you would please.

The question was simple enough. Could a ship with an up-gunned engine ( in this context they were meaning an engine from one class level higher than the actual class of ship...IE a destroyer with an engine rated for a frigate or light cruiser ) gain an extra movement ( Speed ) point ( or two was the actual statement )

I considered the idea and decided to acquiesce to the idea with the following for the houserule.

A ship can gain extra speed by taking a higher class rated engine if it can afford the increase in space. Such a modification would grant said ship a speed bonus of 1 per class difference of engine used.

IE...

Class Engine class Bonus/Reduction

Destroyer Destroyer none

Destroyer Frigate +1 Spd

Destroyer Lt Cruiser +2 Spd

Cruiser Lt Cruiser -1 Spd

Cruiser Frigate -2 Spd

Etc....

As long as the class ship has sufficient space to mount the bigger engines then it can use them to gain additional base speed ( or lose it if its a smaller class )

This idea would allow enterprising GM's to possibly hinder or handicap the RT after severe battle damage that would otherwise limit the RT ship from being able to do anything....giving the RT a chance to continue albeit in a reduced capability ( Great...now i get to chose between shields to take the incoming enemy hits OR shooting back...grrr....) Until such time as the RT ( read as GM ) found an available replacement engine of the same or better class.

Conversely an enterprising RT and lenient GM might acquire a higher class engine to drop into their ship thereby increasing the speed a bit ( and power generated also ) making it possible that the RT might not have to chose between shields or shooting and could now do both....

My idea was that it wasnt an earth shattering game breaking change but has potential for a bit of fun.

Thoughts?

2 hours ago, Cobramax76 said:

My idea was that it wasnt an earth shattering game breaking change but has potential for a bit of fun.

Thoughts?

From one point of view +2/-2 to speed isn't a really big thing. But such adaptability isn't very 40k-ish.

You'd need a hull built for it. Which most of the time probably would be more hassle than starting with a low-end hull of the higher class.

BFG got at least one like this. Long Serpent class battlecruiser has engines of a Retribution battleship (and accordingly "oversized" catastrophic damage effect if those explode). But being between the "proper" tiers is kind of the whole point of battlecruisers.

10 hours ago, TBeholder said:

You'd need a hull built for it. Which most of the time probably would be more hassle than starting with a low-end hull of the higher class.

BFG got at least one like this. Long Serpent class battlecruiser has engines of a Retribution battleship (and accordingly "oversized" catastrophic damage effect if those explode). But being between the "proper" tiers is kind of the whole point of battlecruisers.

Thanks for the info...I don't remember the Long Serpent class at all...at least not right off....Ill have to check it out. Do you remember which book it was located in? ( i might have it just missed it )

As for the specially fitted hull.....I require that the ship need be in drydock for a period of not less than a month not more than 10 months per engine class higher they wanted fit in and the cost of which would be 1PF per class difference ( up OR down ) so it would cost the difference in PF of the engine types as well as the drydock conversion fee. Admittedly much if not all of that cost would be nullified by downgrades since you would still have the original engine to sell off so PF cost would be negligible in some cases BUT....the downtime means the player cannot earn any PF either.....potentially missing out on contracts that could be lucrative so...In essence i made it a minor endeavor in itself to get the refit done if the players wanted it.

13 hours ago, Jargal said:

From one point of view +2/-2 to speed isn't a really big thing. But such adaptability isn't very 40k-ish.

Generally true but it was back in the Heresy era. Jaghati Khan was said to have many of his ships having larger engines and being faster than others of the same class for it. THAT is where my players got the idea from to begin with when i loaned one of them ( the chief instigator in all this ) the first few Horus Heresy books to begin reading. The modification of +/- 1 Spd per class difference isn't meant to be major....just a compromise between saying no and going all in so to speak. The maximum you could probably manage would be a +3 anyway...given the size of the higher class engines is verging on the size of a destroyers total hull size.....so if you used a full sized Cruiser with higher class engines they would look like the description in the Heresy book for it as they would be taking up half the total size of the Cruiser itself...but the size differences would limit the bonus range normally to a max of +2 ( more often only +1 anyway ) And sometimes one of the players mentioned he would be looking at downsizing the engine due to lack of needed power requirements and wanting more space so....it gives them an option as well since your Spd rating has literally no effect during warp transit anyway...( fyi that player is setting up a tramp freighter that will be part of a regular Navy protected convoy for regular PF gains so weapons weren't much of an interest to him ) This is as much about letting them downsize as upgun the engines. This method makes it uniform either direction.

6 hours ago, Cobramax76 said:

The modification of +/- 1 Spd per class difference isn't meant to be major....just a compromise between saying no and going all in so to speak.

Actually we have RAW example of oversized engines, at least for transports, raiders and frigates. Lathe-pattern 2 drive adds +1 Speed, +3 Man in exchange for +2 space and +2 SP, Segrazian "Viperdrive" adds +2/+5 for +4 space, +2 SP and Fragile Engine trait. I don't see why bigger drives can't be scaled the same way.

19 minutes ago, Jargal said:

Actually we have RAW example of oversized engines, at least for transports, raiders and frigates. Lathe-pattern 2 drive adds +1 Speed, +3 Man in exchange for +2 space and +2 SP, Segrazian "Viperdrive" adds +2/+5 for +4 space, +2 SP and Fragile Engine trait. I don't see why bigger drives can't be scaled the same way.

Ahh but those are already included. As for scaling other classes of drives to achieve the same ends...where would we stop at exactly? Up-scaling the drives of a MK2 for destroyers till it fits a MK3 for frigates and lt cruisers? etc.....That option would need a "maximum ceiling" for modifications to add speed and maneuverability etc....This way it stays simple and limits it across the board. If they wanted to take the special drives listed then they could...but then what if they wanted to upgrade them further.....This is a simple across the board modification to existing rules that doesn't generate cause to actually "modify" anything already in game...simply replacing one engine with the next bigger or smaller one.

This way doesn't over complicate things and literally doesn't introduce anything "new" to it.

Speaking of different drives already in game though...What book is the Segrazian "Viperdrive" located? I would like to take a look at that one please.

5 minutes ago, Cobramax76 said:

Speaking of different drives already in game though...What book is the Segrazian "Viperdrive" located? I would like to take a look at that one please.

Hostile Acquisitions, p.69.

5 minutes ago, Cobramax76 said:

Ahh but those are already included. As for scaling other classes of drives to achieve the same ends...where would we stop at exactly?

I meant that my initial statement "not very 40k-ish" isn't very true.

And I forgot one more oversized drive - Mezoa-pattern Theta-7, it's "Viperdrive" for transports, from BFK.

5 minutes ago, Jargal said:

And I forgot one more oversized drive - Mezoa-pattern Theta-7, it's "Viperdrive" for transports, from BFK.

Thanks.

If you just want cool engines, there are upgrades and Archaeotech (umbrella "Modified Drive": Speed +1 Space required -4), plus the Artifact Generator from Stars of Inequity for tweaking quirkier properties.

edit: Long Serpent is from compendium (compilation from White Dwarf, BFG Magazine and other Black Library) PDF, marked as being from BFG Magazine #2.

There are some improvements on less obscure ships, but they don't go this far, e.g. Dauntless has "improved thrusters", giving +1d6 for Full Ahead order, while upgrade Secondary Reactors (translated to RT) gives +2d6.

7 minutes ago, TBeholder said:

If you just want cool engines, there are upgrades and Archaeotech (umbrella "Modified Drive": Speed +1 Space required -4), plus the Artifact Generator from Stars of Inequity for tweaking quirkier properties.

Interesting. ive got the "Advanced Plasma Drives" as is but ill have to look closer at the Artifact Generator i think....thanks.