Suggestion for an improved plague model.

[dogscoff]

EDIT: Disregard this entire post. It doesn't work. There's a better suggested model a few Posts up END EDIT

======================================
Original post begins...

OK, I think the current plague model (level 1, 2, 3... plagues countered by level 1, 2, 3 medical abilities) is far too simple. Here's what I'd like to see...

First up, plague damage to population should be in proportion to the population on a planet, not a set figure which applies to any planet.

Secondly, plagues should be able to spread from planet to planet, including to neighbouring allied planets. Planets with space ports should be particularly at risk.

Right, now onto the complex bit:
A plague's severity should be measured as a percentage. 0% means no plague. A small number, for example a 3% severity plague, would be easy to cure, and would cause only a little anger on a planet. It would kill some, but not many of the population, and could probably even be an acceptable long-term status for a planet.
On the other hand, a 90% plague would be catastrophic, and would bring production to a complete halt, threatening to wipe the planet out in a few turns.

The first cool thing about this suggested system is that the plague severity value could change from turn to turn. A planet with a 30% plague might go up to 40% if a combat occurred on the planet, or if another plague bomb was dropped. All sorts of other factors could be worked out to modify the plague severity from turn to turn. Random modifiers (positive and negative) from turn to turn would be a good thing.

Curing a plague would require a ship with a "cure level" higher than the severity of plague. For example, a med bay II might have a cure level of 30, and so be able to completely cure plagues of 30% and below. Simple so far, eh?

Cool thing #2: A ship with cure level 30 can't cure a plague with a severity greater than 30%, but it can "reduce the symptoms". It reduces the plague severity by either its cure level (in this case 30 points), or to a severity slightly above it's own cure level (say, cure level + 10), whichever is the higher.

For example, ship cure level is 30, plague severity is 55%. The ship can't cure the plague, but it can reduce the severity. Reducing it by 30 would bring it down to 25%, which would make it curable. This would be pointless in game terms, so instead it reduces it to 30+10=40. The plague is made less severe, but still can't be cured by a cure level 30 med bay. Geddit?

In the event that two or more medical ships are in attendance, all calculations are based on the highest-rated ship, with a +10% of level modifer for each additional med ship in the sector. Confused? Example:

Say you had a cure level 70 ship, a level 60 and a level 50. The plague is at 84%. On the first turn the game takes the highest cure value (70) and modifies it by 10% of each additional cure value. (10%of 60 + 10%of 50=11 )That makes a cure level of 70+11=81, which can't cure the 84% plague outright. However, like in the first example, it reduces the plague severity from 84% to 70+10=80% (notice that the unmodified cure level is used at for this Last calculation. There's a reason for this.)

For the next turn (we'll ignore any factors which may have made the plague worse), we see that combined "cure power" of the 3 ships (70+5+6) is enough to cure the plague, which is now 80% severity.

This means that lots and lots of med ships can "gang up" on a plague to cure it. They should therefore be pretty expensive. There is a potential exploit there using the "+10 if can't cure" rule, but external severity-modifying factors will go some way to negating this.

For further complication a med bay's cure level is also variable over time. The base level of 30 for a med bay II could be augmented each time it successfully cures a plague (experience). Finally, medical facilities on-planet could provide a system-wide "cure boost", which alters the cure level again. These same facilities could reduce the spread of disease from planet to planet.

Finally, curing a plague outright would be a slow process. Assuming the ship or ships have a higher cure level than the plague severity, it might take several turns to reduce the severity all the way down to 0%, depending on the comparative values of the plague and cure. The same would apply when a ship reduces the severity of a plague it can't cure. This would give the plague a chance to "flare up" again if some external event prompted it.

That's about it. I know it looks horribly complicated from my explanation, but it's actually reasonable simple. Ish. From the player's point of view it would be clear what level of medical technology is required to cure a plague, but at the same time the plague would appear to have the unpredictability of an organic system. It would certainly make a lot more sense and provide a lot more challenge than the current system, anyway.

[ August 29, 2002, 16:30: Message edited by: dogscoff ]

[dogscoff]

Actually, I've just re-read what I've written and it's full of possible exploits. i think I need to re-think it a little...

[Krsqk]

I've read through it a couple of times, and I didn't notice anything to exploit. What are you seeing?

How about, in addition to the component's cure rating, adding the ship's experience to it, and giving experience for successfully curing a plague? So a ship with cure rating 30% and 15% experience would cure 45% plagues. I think it's quite reasonable to assume medical ships would receive different training at training facilities than combat ships would. Of course, you'd have some doofus putting guns on their medical ship and hunting down lone colony ships to boost their experience, but then some people are doofuses. (Doofusi?)

[Edit/addendum]
You could also increase the risk of plague to your own planets by building plague bomb-equipped ships or launching plague intel projects (if modded in)--you know, working with hazardous biological materials more often and increasing the risk of outbreak. Just a thought.

[ August 29, 2002, 13:25: Message edited by: Krsqk ]

[Jmenschenfresser]

I think you could simplify the math a little on the curing part if you gave the medical bays a cure rate.

And give plagues an infection rate.

So someone drops a lvl 1 plague bomb on your planet. It starts at 10% plagued and increases at a rate of 1% per turn. Something like that.

You then move a lvl 1 medical bay over the planet. It has a reduction rate of 2%. The percentages are then just treated like simple integers, and you arrive at a reduction rate of -1%. And you could make medical bays stack to cure plagues faster.

I'm not actually sure how you'd figure deaths, because a 10% plague will reduce your population quickly if you figure 10% dying every turn. I guess theoretically you can never get to zero population.

Dunno, just suggestions.

[dogscoff]

Yeah, okay, forget all that other stuff I typed down in my original post. How about we start with this, and try to build some of the more advanced features into it:

Plague Severity:
================
-All colonised planets have a plague severity value, measured as a percentage. 0% means no plague. 100% is the nastiest plague you can get.

-Every complete 5% of plague severity kills 2% of the planet's population per turn (rounded up). This means plagues of less than 5% have no effect. However, a 50% plague would kill 20 million population on a planet with 100m. The next turn it would kill 16m of the remaining 80m, then 13m...

-The severity should also affect the change in the population's anger. Low severity=slowly gets angry. High severity=instant rioting.

-Random plague events, plague bombs and plague intel would be implemented by simply adding a given value to a planet's plague severity.

-Every planet with more than 10% plague adds to the plague severity of each friendly planet in the system. Normal planets would be incremented by 1% per plagued planet per turn. Planets with a spaceport will go up by 2% per plagued planet per turn. Blockaded planets will not receive this increment.

-Ground combat on a planet increments its plague level slightly, due to homes and sanitation infrastructure being destroyed, medical staff diverted etc. The extent of the increment should depend on the duration of combat.

-Ditto for orbital bombarment, except that it's not duration but damage to population and facilities that governs the extent of the increment.

-The extent of ground/ orbital combat increments should be be subject to values in settings.txt.

-A random factor of a few percent is also introduced each turn which could be positive or negative. For planets with less than 5% severity, this random factor should lean heavily toward the negative. (ie minor plagues tend to cure themselves) It would be nice if this was moddable in settings.txt.

-It would be cool if plague could be carried by population in cargo as well, but it would probably be too hard to implement.

Medical ships & med levels:
===========================
-All ships have a "med level" from 0 to 100. This med level takes a base value from an installed med bay component when the ship is built. Only one med component per ship is effective, but backups may be installed.

-When a medbay component is destroyed or retrofitted out, its med value is subtracted from the ship's med level.

-When a medbay component is repaired or retrofitted in, its med value is added to the ship's med level.

-Med levels are modified by experience as follows: On each planet, every 10% of severity reduction in a single turn grants 1% medical experience to every ship in orbit. Ships with a med level of 0% do not benefit from this bonus.

-A cheap "sick bay" component should be available from the start of the game with a med level of just 1 or 2.

-System and sector wide facilities could be available to temporarily modify the med levels of nearby ships.

Curing plagues
==============
-If the plague severity is higher than the med level of an orbitting ship, then that ship does not "qualify" to cure the plague and has no effect on it.

-Plague curing using medical ships is calculated as follows:
The med levels of all qualifying ships are totalled up. That total is then divided by 5 and deducted from the plague severity.

There. Much more simple, but pretty much exploit-proof and still an improvement on the existing system. Obviously the numbers could be tweaked (and modded). Opinions?

Anyone got any ideas for more advanced features tht could slot in there?

[ August 29, 2002, 16:34: Message edited by: dogscoff ]

[dogscoff]

The exploit was that you could send a med ship with a cure level of 10 to a planet with a severity 80 plague. The med ship would (eventually) bring the severity down to 20, and then you could send in your other med ship (with cure level 20) to finish the job.

I like my second Version better=-) You lose the "low level ships can partially cure high level plagues" bit, but it's much simpler and maybe that could be added in some other way. It's still an improvement over the existing system.

Oh, and I love the idea of increased risks from messing around with biological weapons.

Infection rates would be cool but it would mean an awful lot more data to track. Would be very cool though.