Hello, the PDF attached at the website was meant more as a design note than a guide to monster creation. We kinda rushed that one out, so I'll try to add to that information here, and we'll have to revise the posted doc after that.
TY: No problems here, assuming types are purely narrative description and the game doesn't have a specific list of types that grant particular abilities?
Most are purely narrative. However, "legendary creatures" unarmed attacks ignore normal and preternatural armor. A preternatural creature's (one rank beneath legendary) unarmed attacks ignore 3 to 8 poitns of armor protection (rolling 1D6 +2), but preternatural armor negates this advantage. Legendary types include angels, demons, dragons, some undead, and some fey. Preternatural types include most fey, "eldritch beasts", extraplanar creatures, shapechangers, and undead.
Threat Rank: For all monsters other than Full-Fledged (who would use the full skill system, right?), you just need dice in Close Combat, Range Combat, and/or Magic Combat? The specific details of the attack (sharp claws, magic beams shooting from the eyes, spitting acid, soul-draining touch) are just flavor and mechanically they're all the same?
Yes, that's true. I might list the threat ranks as: Melee, Unarmed [both close attacks], Ranged, and Arcane. For purposes of Challenge Score the core rules only take the highest value (max-rank-value) of each category into account.
Extra Attacks: Not at all clear on how this works, and not a single example monster I've seen actually has extra attacks so I have no idea what it would look like for something to have extra attacks. I vaguely recall reading a post about it somewhere, but now I can't seem to find it.
from the core rules: Extra Attacks: some monsters have special, extra attacks, in addition to their regular attacks. Each additional attack is listed in any monster stat bloc after the abbreviation “EA,” and can be of any type (physical, mental, magical, etc), and take any form (claws, bite, fire breath, psionic attack, etc). The Potential-Harm of an Extra attack follows the standard rules (like a maximum of three dice in a single ADC, or “max-split” limitations based on weapon or attack form). Otherwise, a creature may have any number of Extra Attacks in a round, limited only by its concept. This rule better simulates special creatures with unusual attack combinations—hellhounds, multi-limbed demons or golems, giant squid, giant snakes, dragons, two-headed giants with psychogenic powers, the ever loved hydras, and so on.
Do not confuse an Extra Attack category with multiple attacks achieved by “splitting” a dice pool (see Max-Split). In fact, some creatures’ Extra Attacks are additional ADCs, divisible into yet more attacks. These special, extra attacks always occur one phase after the creature’s regular attacks in a round.
For example, imagine a humanoid monster with four arms, and just to make it really frightening, it is wielding in each hand a magic bludgeon, each club inflicting +1 threat points, plus an extra 1D6 of fire-based Potential-Harm (as a magic Harm effect). For illustration, consider its template:
Le Monstre Supplémentaire D'attaque
TR: Melee 3D8 (+1 and +1D6 fire), Unarmed 1D4, Ranged D6, Arcane n/a
EA: 2D8 (+1 and +1D6 fire)
EA: 1D8 (+1 and +1D6 fire)
EA: 1D8 (+1 and +1D6 fire)
BP: D10 (13 with club, allow it to act in phase D12)
Notes: Each club (+1 harm, max-split 2, init bonus +3) wielded is magical, granting an additional +1 to threat points, plus an extra 1D6 to Potential-Harm with every strike, treated as a Harm Effect spell.
Example of Battle: this dangerous Supplémentaire (or whatever the GM calls it) attacks a terrified soldier in phase D12, using its clubs, and decides to split its regular Melee ADC by the maximum allowed by the weapon type (max-split 2). So the GM rolls against the monster’s target: tossing down 1D8 + 2 (multiple attack 1) and then adding 1D6 (as magic Harm), and then rolling another 2D8+2 (multiple attack 2), plus 1D6 (as magic Harm) against the same target. The threat points penetrate the hapless foe’s defenses, killing him. But Le Monstre is not finished. Turning to the next foe, in the very next battle phase (of the same round), it uses its extra limbs to attack three more times (2D8, then 1D8, then 1D8). Remember to allow a targeted foe his armor roll whenever applicable; never roll individual Extra Attacks all at once and add the damage of all those ADCs cumulatively (doing such would be grossly unfair).
Extra Attacks and Challenge Score: As mentioned in the Challenge Score section, these Extra Attacks add ½ of their cumulative MRV to CS. How did we calculate this Challenge Score? First, add up the highest Potential-Harm in close (melee or unarmed), missile (aka ranged), or magic (aka arcane) categories. For Le Monstre, those numbers add up to 30 (3x8 + 6, ignoring the 4) + 16 ( ½ value of extra attacks) + 16 (magic and ½ value Die-Rank bonuses). Note the magic clubs’ threat points bonus applies only once to any ADC, whether primary attack or extra attack, even if the creature has the potential to split the ADC.
GM Notes: “Fodder” type creatures generally do not possess extra attacks, but as is the case with most rules, such is only a guideline for the GM to consider. In addition, Extra Attacks for Monsters are different from an “Extra Attack” advantage for full-fledged characters, an ability governed by different, more limiting rules.
Hit Points: The multiplier is basically just an arbitrary number you choose to make your monster tougher? The sample goblin has a multiplier of 2, but I have no idea where it comes from mechanically. Or wait, is that because it's a medium creature? If so, are there particular multipliers that correspond to particular sizes? If something had a "thick scaly hide", would that be a hitpoint modifier, or would that work like armor with a die type?
Actually, multipliers to hitpoints (or resilience) is based on a number of factors that are spelled out in the book. So a medium creature has no modifier based on size. Larger and above will have an increase to its HP (note that these rules do not translate exactly into full-fledged characters, but that's another issue). So...
Large: x4 to HP.
Huge: x6 to HP.
Preternatural = x2 to x3 toward HP and/or RS.
Legendary = x 4 to x5 toward HP and/or RS.
Resilience: Pretty straightforward, but is there wiggle room? If I want my critter to be just slightly more resilient is there any reason I couldn't give it 1/2hitpoints + 1?
That's fine. Anything like that can be easily added to the "notes" section of the monster description.
Battle Phase: A question not really related to creature making: some weapons give an initiative bonus. How does that work exactly? If an axe gives +2 init, does that take you from D4 to D6? If so, would a D12 + axe put you at D14 even though that doesn't correspond to an actual die type? If a D6 is "fair", what are the names for the other ranks?
Yes, the axe would bring the wielder who is specialized in axes from D4 to D6. And yes, the D12 would then be a D14.
Here are the battle phases, with their names and the corresponding die-ranks. As you can see some creatures may have above D12.
Battle Phase L (Legendary Init) D20
Battle Phase I (Incredible Initiative) D16
Battle Phase 1 (Superb Initiative) D12
Battle Phase 2 (Great Initiative) D10
Battle Phase 3 (Good Initiative) D8
Battle Phase 4 (Fair Initiative) D6
Battle Phase 5 (Average Initiative) D4
Battle Phase P (Poor Initiative) D3
Battle Phase T (Terrible Initiative) D2
Once I get answers to these questions, I think I'd feel comfortable enough to create a few monsters, but ones without any special abilities like the disease-giving rat posted in another thread.
For special abilities is helps to be familiar with the magical Effects rules, which can translate (mechanically) into non-magical effects as well. For now, I can help translate the idea into game mechanics, so don't hesitate to throw it in there.
EDIT: Also, all the example monsters I've seen posted are pretty low-end. Could you give a few examples of what a big tough nasty not-full-fledged thing would look like?
How about this terror?
TY/CS: colossal red dragon / 544 (+10 due to extra attacks) (t's adversaries would need to have a combined Potential-Harm each round of 544).
TR: 3D12 Bite +12 (razor sharp fangs, max-split 0), No Mundane Ranged, 3D20 Fire Breath (area-effect of 50' diameter).
EA: 2D10 Claw +10 (razor sharp talons, max-split 2)
HP: 1512 (x10 for size and x4 for nature in this case)
RS: 1512 (because primary attack is arcane, 100% of HP).