(Answered) Terrain factor - when is it reduced

[Alfaryn]

Reading the rules on clearing woods (and the example included in them) (p. 112 TW / p. 61 BMM / p. 9 Hexpack: Lakes and Rivers booklet) I understood that to reduce a woods hex to a new terrain type the damage you need to deal to the hex must exceed (not just equal) the difference between the Terrain Factor (TF) of the old and the new terrain type. For example to reduce a Heavy Woods (TF 90) to a Light Woods hex (TF 50) you need to deal at least 41 points of damage (dealing just 40 points of damage would  result in a TF 50 hex, but still treated as Heavy Woods which may be somewhat counter-intuitive, but that is what the rules in TW/BMM seem to say). To reduce a Light Woods hex (TF 50) to a Rough hex (TF 0) you need to deal at least 51 points of damage and so on...

Now I've read the Terrain Factor rules beginning on p. 64 TO, and spotted several problems, which may mean, that either the above rules interpretation may be incorrect. The first problem is that the TO rules don't explicitly say at which points the terrain types listed in the table on p. 64 TO are reduced to a new type. This is a smaller problem, as I would assume, that the rules from TW/BMM apply here accordingly. The second problem is a bit bigger however - on p. 65-66 TO it is stated several times that TF of a hex is tracked until it reduced to 0 (not bellow 0, just to 0), that planetary conditions on hexes where DropShips landed are reduced to 0 (not bellow 0) and so on, which would suggest that terrain becomes clear/rough as soon as it's TF equals 0 (not -1, as TW/BMM rules would suggest).

Apparently there seems to be an error in one set of rules:
- either TW/BMM/Hexpack: Lakes and Rivers is correct in which case the rules in the TO need to be fixed to reflect the fact, that terrain reduction to Clear/Rough (or Rough Sublevel 1 in case of Clear/Rough terrain that continues to take punishment as described on p. 66 TO under Terrain Displacement) happens at -1 TF,
- or TO is correct in which case the rules in TW/BMM/Hexpack: Lakes and Rivers need fixing to say that the terrain is reduced when the damage you dealt to the hex equals or exceeds (not just exceed) the difference between the Terrain Factor (TF) of the old and the new terrain type, and the example included in those rules needs to reflect this (it needs to say, that a heavy woods hex that already took 35 points of damage needs to take only 5 points of damage to be reduced to light woods, as the rules say now).

So how do the rules work exactly? Is on of the rule sets wrong or did I manage to completely misunderstand something here?

[Xotl]

The rules don't contradict each other; it's just that 0 breaks the pattern (because tracking below 0 would be silly).  It would have been better if it was equal to instead of below, I agree, but that's legacy rules for you.

So follow the rules as written in all cases. 

[Alfaryn]

Thank you.

I guess it means, that the text in TO is supposed to mean, if hex's TF reaches exactly 0, I still need to "track" the fact that as soon as the hex receives any further damage it is reduced to rough? Aside from the fact, that the "reduction happens at equal or bellow TF printed threshold"  rather than just "ellow" would be easier to follow, I think the TO rules could phrased a bit better, but I understand, that reviewing and rewriting all such rough edges in the rules wouldn't be exactly feasible with resources you have. C'est la vie.

Edit: Sorry for the crossed out bit above. Looks like I misunderstood your answer or misremembered what the books say when I posted last time.

The problem is that your answer contradicts TW, BMM and the Hex Pack. Of course we agree, that the way to change the rules, that would be easiest to follow would be to reduce any sort of terrain to a new type, when TF is bellow or equal to maximum TF of the new terrain type in every case, but even if you rule, that TF 0 should be the special case there is nothing in TW, BMM or the Hex Pax booklet, that supports it. They only say that terrain is reduced to new type, when its TF drops bellow TF of the new terrain type. Considering that under those rules Rough terrain has TF of 0, then to be reduced to rough the hex's TF needs to be lover then 0 (in other words -1 or less), so both your answer and TO go against TW, BMM and the Hex Pack booklet.

If your answer is correct, then it is those last three books need an errata. Either TF of rough terrain provided in those books needs to change to 1, or the threshold of terrain reduction needs to change from "bellow maximum TF of the new terrain type" to "bellow or equal...".

As a side note I've checked my old Polish Battletech rulebook "Battletech: Kompendium Edycja Polska" (p. 69) published in 1996, and to my surprise this book handles reduction of woods hexes in a completely different way, then modern books do. There is no TF. Instead the book provides a list of weapons, that are incapable of reducing terrain (small lasers, MGs, AC/2, AC/5, and SRM 2), and says that any other weapon takes just one hit to reduce terrain by one step (from heavy woods to light woods, from light woods to rough), so unless this rule was changed specifically for the Polish edition (and I can see no reason why it would be the case), TW terrain reduction rules may be not be such an old "legacy" as one might think at first (though they may still pre-date TW by quite a few years), and since it was changed before in such a drastic way, maybe something as small as shifting terrain reduction threshold by one point (from bellow maximum TF of the new terrain to bellow or equal) isn't as sacrilegious as it first appeared?  ;)

[Xotl]

My answer said "both are right; use the text as written".  How do you get a contradiction out of that?  Just make an exception for 0.

TW text: "Regardless of a woods hex’s current Terrain Factor, its type does not change until the TF falls below the value of the reduced hex."

So a Heavy Woods reduced to anywhere from 49-1 TF becomes a Light Woods; upon reaching 0 TF it becomes Rough.  It doesn't expressly say "make an exception for Rough and 0 damage instead of -1 damage", but IMO it's kind of screamingly obvious that you should do so and the table shows that as occurring besides.

The TO text doesn't repeat the TW text because it's an expansion of the TW text: it naturally assumes you know the previous iteration that is it building off of.  So Ultra-Heavy Woods would drop to Heavy Woods once the hex reaches 89 TF, and so on, following established TW precedent, all the way down to a standard 0.  No errata is needed.

Also, it's funny that I never noticed you were Polish before (the commas before "that" are a dead giveaway).

[Alfaryn]

So a Heavy Woods reduced to anywhere from 49-1 TF becomes a Light Woods; upon reaching 0 TF it becomes Rough.  It doesn't expressly say "make an exception for Rough and 0 damage instead of -1 damage", but IMO it's kind of screamingly obvious that you should do so and the table shows that as occurring besides.

My problem with the above argument is that the table in question suggests that Light Woods get reduced to Rough at 0 TF only as much as it suggests, that Heavy Woods get reduced to Light Woods at 50 TF. What you seem to say is that in one of the above cases I should stick to the literal interpretation of the rules, but in the other I should make exception towards what intuition says is "screamingly obvious" only because otherwise I would end up with a threshold that is a negative number. Why is it not equally "screamingly obvious" from the table, that Heavy Woods are not reduced to Light Woods at 50 instead 49 TF?  It does not seem like an internally consistent approach. Either the rule should be applied literally or not.

I agree that it seems natural that just bringing terrain to 0 TF should be sufficient to reduce it to rough (or whatever is the final "utterly destroyed" state for a given hex), but since this entire rule looks to me as if somebody just originally planned to write "Regardless of a woods hex’s current Terrain Factor, its type does not change until the TF falls to or below the value of the reduced hex.", and later (possibly in a later edition of the rules) somebody else saw that people have a problem following this rule as it was written (because let's face it if somebody sees in the table that Light Woods has TF 50 and Rough has TF 0, they are going to assume that as soon as a Heavy Woods hex has 50 TF left it should be treated as a Light Woods hex, and as soon as any Woods hex has 0 TF left it should be treated as Rough), and added the example about 35 + 6 damage needed to change Heavy Woods to Light Woods to drive it home that that the rule as written says that you need to be below, not at or below TF of the reduced terrain. Which would mean that the example in question may be a result of someone noticing what was in fact a simple error in the rule and instead of correcting the rule, thinking that people just get it wrong because it seems more intuitive that way.

Maybe it is just me. I guess it is not obvious to me that the Woods are reduced to Rough terrain at 0 TF (as opposed to -1 TF), because I find this whole rule counter-intuitive not just for the 0 TF case, but for all cases when you reach TF of a new terrain type. My instincts just keep telling me that it really should work not as it is written, but as I described above, and when I run into a rule that works differently then I expect it to do, I try to interpret the rule in the most literal way possible, without any presumptions to see if it is at least internally consistent, and in this case the fact that Woods turn into Rough at 0 TF is spelled out in TO, but seems like a presumption on TW/BMM, where at least to me it seems, that literal interpretation of the rules results at reduction to Rough only at -1 TF or lower.

It may even be since there are so many weapons (especially long range ones) with damage divisible by 5 or even 10 that someone could have decided that having Heavy Woods reduced to Light Woods after taking exactly 4 PPC shoots for example is a little too easy for a pair of Warhammers or something like that, and the rules should require one extra point of damage accomplish it - hence the current rule.

The reason I checked that old Polish rulebook was to see if there was an identical rule, but without the example which in my opinion would make my theory that there is an error in the TW rule more likely, since if the example appeared later then the rule, it could have been written by a different person, who could have misinterpreted the intent of the rule's author. It was quite a surprise to see that the rule itself was so different then.

Whether my theory is right or wrong I don't plan to post anything more in this thread, as I am probably overthinking this entire topic and just wasting both my and your time. A one point difference in such rarely used rule will rarely come to play anyway. I brought to your attention what I thought (and still think) can be a rule requiring an errata and explained why as well as I could. It is for you to decide what the official rules should be, and if I disagree with your decision, I can always modify the rules for my own games.

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As for me being Polish, and you not noticing it - I often post at strange hours (like 1 to 5 in the morning), so you could have an impression that I post from a time zone that has nothing to do with Europe.

Sorry about the commas. I'll try to do better in the future although I can't promise to always get it right, since I always had problems with following punctuation rules, and on top of it some of those rules are a bit different in Polish than in English - especially the ones governing use of commas in complex and compound sentences. Looks like I need a refresher on those, since I probably fell into a trap of memorising which conjunctions are usually preceded by commas, and which don't (and memorising them incorrectly in case of English conjunctions) instead of doing it the hard by correct way - that is consciously thinking where clauses in my sentences are exactly, and which of them should be separated with commas.

[Xotl]

Sorry about the commas. I'll try to do better in the future although I can't promise to always get it right, since I always had problems with following punctuation rules, and on top of it

I would say that, if I may, in general you have a bit of a tendency to overthink things.  I certainly wasn't admonishing you or insisting you fix your comma usage; your English is certainly better than my bardzo źle Polish.  It was just something I'm familiar with on the other end from trying to learn Polish.  I had wondered if Polish speakers learning English had the habit you do, and lo and behold, it seems they do.  It's just neat, that's all: nothing more.

Cheers.