Background:
Yes, there are still issues in this, sorry!
Mahkra's post best covered many of them, even though related directly to an 'entering impassable terrain' argument. So here it is;
<Mahkra>I thought the original rules seemed pretty clear, at least in the vanilla expansions, though there's never been a defined general "Movement Sequence" like the Attack Sequence in the JitD rules. We were just given specific instruction for each new type of space. We were usually even given specific instruction regarding large monsters.
(Parts relevant to large monsters in bold below.)
Rubble: "blocks both figure movement and line of sight."
Pit: "if a hero or monster moves so that the figure is only occupying pit spaces, the figure falls into the pit."
Mud: "a small figure must spend 2 movement points ... to move onto a mud space" ... "
large figures are affected by mud, but only if they make a move that results in the entire figure occupying mud spaces."
Dart Fields: "each time a hero or monster moves so that
any part of the figure
is occupying a dart field space, it risks being hit by a dart."
Fog: "Figures have line of sight into adjacent fog spaces.
A figure in a fog space
has line of sight to all adjacent spaces, but not to any other spaces."
Tree: "It costs two movement points to enter a tree space. A figure in a tree space is considered to have the Shadowcloak ability. l
arge monsters only need to occupy one tree space to benefit from this ability.
"
Though we're never given a Movement Sequence, I imagine moving to an adjacent space actually involves the following steps:
1. Determine whether the intended adjacent space can be legally occupied. (e.g. not Rubble)
2. Determine the cost (generally MP cost) to move to the intended space.
3. If sufficient MP to pay the cost, move figure to adjacent space, paying MP cost.
4. Suffer any immediate effects of occupation. (e.g. damage from lava)
5. Suffer any prolonged effects as long as that space is occupied. (e.g. restricted LoS in Pit or Fog, Shadowcloak in Tree)
Then came the FAQ ruling:
When large monsters move, they can sometimes find themselves moving across hazardous terrain (lava, scything blades) twice as often as
other figures. Further, it can often be confusing whether or not beneficial terrain (trees, elevated terrain) should affect a creature
only partly standing on it. Use the following guidelines to arbitrate these instances.
The overlord may choose to have a monster affected by any terrain it partially occupies. A monster MUST be affected by any terrain it
completely occupies. If the monster is completely occupying multiple terrains, the figure has to be affected by one of the terrains
(Overlord's choice).
This FAQ ruling superficially seems rather simple, and it does negate one rules loophole for the OL:
* If a large monster is half in mud and half in lava, it now must be affected by one of the two, instead of being able to use each to be
safe from the other.
However, it also raises numerous questions, some of which have been discussed in other places and remain ambiguous:
* When does the OL choose? How long does that choice last? When, if ever, can he change his decision?
* Must the overlord choose to have a monster affected by any single terrain, or could he choose to consider a monster in a tree and on a throne?
* What is considered "terrain"? That term is used in a few places in the FAQ but is never defined. And it's not really used in the rule books. (It's mentioned in component descriptions for RtL/ToI/SoB - map tiles have "dungeon terrain" or "outdoor terrain" - but it's only used in the actual rules once, in the "Rope" part of the SoB rules, and it is never defined. I'd guess that Lava and Mud are probably terrain, at least thematically, but is Fog? Dart Fields? Pits? Rubble?)
* As written, the OL only has a choice about the terrains currently occupied, which means the OL cannot choose to ignore the added cost to move its front half onto a mud space or a tree. I imagine the rule is intended to function the way the rules were written in the WoD and ToI rules, though, and the OL should be able to choose to ignore terrain that the figure does not already occupy but will occupy after movement.
Assuming we can get past those issues, I'm still not sure what the FAQ means by "may choose to have a monster affected by any terrain". This
could plausibly mean a few different things.
A. The OL may choose to ignore occupation effects, such as Fog / Lava / Tree, but must still pay applicable entry costs per the normal rules. (# 4, 5 are conditional in the Sequence above.)
B. The OL may choose to ignore entry costs and occupation effects, but still may not move onto any space that could not be legally occupied by a small figure. (# 2, 4, 5 are conditional.)
C. The OL may choose to ignore ALL effects of a certain terrain, as long as the movement does not result in the entire base being in that terrain type. (# 1, 2, 4, 5 are conditional.)
D. (Something else I haven't considered?)
I believe "B" is Corbon's interpretation. "C" would allow large monsters to occupy rubble and water. But the right answer might also be "A"; I'm not sure why to believe any one of these options is more valid than any other.</Mahkra>
So, it really does seem that the large monsters + terrain needs rewriting right from scratch.
Suggestion:
Replace the Large monster movement section (at least the rules portion) with...
When a large monster moves, several things happen:
* it enters one or more new spaces that it did not previously occupy. When this happens it may choose to count one and only one of the newly entered spaces as 'the' space it is entering. The large monster is then treated as if only moving into that space for the purposes of effects that are triggered when entering a space (eg Mud, Lava, Aura).
* it occupies multiple spaces. At all times, every space that a large monster occupies must be a space that it could legally enter if it was a small monster.
<OR replace last sentence with "A large monster may occupy impassable spaces as long as it is not occupying impassable spaces with all of its spaces">
* it occupies multiple spaces. A large monster may claim a beneficial effect from any terrain (obstacle or other prop) space it occupies (eg if one space is in a tree the entire monster has shadowcloak).
<OPTIONAL ADDITION>
* it occupies multiple spaces. When a large monster makes an attack it may choose one and only one space that it occupies to make that attack from. For the purposes of LOS, adjacency, range to target space, Template placement and terrain (obstacles and other props) the attack comes only from that space. For all other affects (eg Command, spaces affected by an AoE attack) the monster may count any and all spaces it occupies for each affect.
Notes For FFG:
The first * covers moving into multiple new terrain types and I think has the same net effect as the current rules.
The second * covers the question on impassable terrain - one way or the other.
The third * covers beneficial effects. Now there is no question of choosing etc.A monster may move into a tree without paying the cost using the first *, then later claim the benefit using this third *. I believe this is how the current wording acts.
The fourth * is an entirely new rule that might be beneficial and might not. FFG can decide. (Or we can drop it before we send to FFG. I personally favour it because it tidies up some small inconsistencies in general play - like hitting with a melee attack from an elevated position even though the target is not adjacent to the elevation for example).
Notes for forum commentators:
Possible issue with the first * - Alertness (and similar). Not quite sure how to get around that yet... Please give ideas!