I've noted several times in the course of this series that growing up with D&D and video games may have adversely affected our games, leading to a more kick-in-the-door/hack-and-slash style of play. But even in those early games, there were times when we would converse with monsters, and sometimes even making friends (or making enemies out of what could have been allies). A lot of times it depended on the mood we were in.
This section starts out saying, "Many non-human monsters have infravision, in addition to normal sight" (p. 22). It then explains the basics of infravision -- see heat, normal light disrupts it, halflings and thieves can't hide in complete darkness from it, but if there is light casting shadows they can.
Now, I remember reading somewhere that in OD&D, all 'monsters' (by some interpretations even human monsters like bandits) have infravision when in the dungeon. No, it makes no sense, but it does explain why everything in the dungeon is in complete darkness until the PCs arrive. Here, we don't have anything so broad (human monsters are excluded). But reading that line, I asked myself how many monsters are listed as having infravision? And it turns out, there are only five (or seven) creatures explicitly noted as having it: gnome, goblin, kobold, tuatara (giant lizard), and pit viper (snake). The entry for the dwarf and elf don't mention it, but since the character class descriptions do, it can be safe to assume the monster types do as well. Five (or seven) isn't really many, especially considering there are about 100 types of monsters listed in the book.
So that leads to a question. The dwarf and elf aren't listed as having it in their description. The gnome, goblin and kobold all have notes as having "exceptional infravision, 90' range" and the tuatara and pit viper seem to have it listed to show they are exceptions among the giant lizards and snakes (the other types don't). Which monsters, actually, have infravision?
From the above, it would seem that all humanoid type monsters have it (bugbears, dwarves, elves, gnolls, hobgoblins, lizard men, medusa (?), ogres, orcs, pixies, sprites, thouls, troglodytes all have normal 60' type, the three explicitly listed as having it above have exceptional 90' type. Most normal animals do not. Human monsters (bandit, berserker, human*, normal human*, NPC party) do not. Everything else, from slimes to dragons, is up to the DM. It does say "many" not "most" so this seems to be a fair interpretation.
A strict reading, though, limits the monsters with infravision to five or seven only.
*Yes, I'll get into the fact that "0-level" NPC humans are listed twice later in the series.
Monsters use d8s for hit points, and the hit dice tell you how many dice to roll, and give you an idea of how big and/or tough the monster is. There are lots of examples explaining the addition or subtraction of extra hit points for some monsters (like Hit Dice 3+1). Nothing special here.
Frank explains that many dungeons are bigger than just a few caves (like in the players' book tutorial), and have multiple levels (like in the "first group adventure" in this book). Deeper (or higher or farther back) areas get more dangerous and have greater treasures. This section basically lays out to the new DM that multi-level dungeons are a risk-reward system.
Monster level is equal to hit dice, ignoring any plus or minus. Monsters are usually encountered on the dungeon level equal to their monster level, and rarely more than three levels different. Again, we're getting the risk-reward structure of dungeon delving explained to us.
Number of Monsters
The fourth part of this risk-reward system's explanation tells us to adjust the standard number appearing when monsters are on a level higher or lower than their normal level. So bugbears may be found on level 1, but not very many will be in one encounter. If bugbears are encountered below dungeon level 3, there should be more than the normal number appearing.
The DM may change the number appearing as desired. These guidelines are not rules, but are offered to help in creating good, fair dungeons. If low level characters encounter tough monsters on the first and second levels of a dungeon, they might be overpowered. Even using these guidelines, they might encounter dangerous monsters, but in very small numbers. (p. 22)Now, some might say that what Frank is saying here is just the same thing as 3E/Pathfinder's Challenge Rating/Encounter Level system, or 4E's encounter budgets (I think that's what they were called). And the intention is the same, but the execution -- at least as far as I've seen it done in 3E/4E, was quite different.
Here, we've got a location divided by regions of increasing danger (and potential reward). Players choose what danger level they want, and the commensurate amount of reward they expect to gain for it. The DM just sets up the situation and lets players decide. If 7th level PCs want to tromp around Dungeon Level 1, smacking around orcs and kobolds, and getting a few hundred silver coins for their effort, that's their choice. If 2nd level PCs want to attempt a quick foray down to Dungeon Level 5 to try and score one big haul, that's also their choice. That's the intent here.
Now, in newer editions, sure you can set up the game that way. But most games I've played in, and most adventure modules I've read for these editions, don't do that. You're not expected to try and run low level characters through Heart of Nightfang Spire (10th level adventure) just to see if they can score one big treasure haul and then retreat. The lack of officially awarding XP for gold discourages this, actually.
When Frank talks about setting up a fair game here, he's not talking about setting up encounters only of the appropriate level for the PCs. He's saying don't stick a sabertooth tiger or red dragon on level 1 without any warning, because the players should have the the agency to choose their level of danger and commensurate reward. If they get in over their heads, it should be their own fault, not the DM's. At the same time, it's not the DM's job to prevent them from getting in over their heads IF THEY SO CHOOSE.
And here we have the much lauded (recently, anyway) Monster Reaction Chart. Unless badly influenced by video games (as I sometimes was as a youth), monsters may not always just attack when encountered (although Frank does note that some monsters will, and if so it's noted in their descriptions). Like others, I've found this chart to be a great way to work out all sorts of social situations besides simply deciding if the monsters attack, negotiate, leave, or act friendly.
There are two things that can influence the roll: character actions, and Charisma scores. For character actions, talk or gestures might affect the roll, from a -2 penalty up to a +2 bonus. If the PCs can speak the language of the monster or vice versa, then Charisma modifiers also affect the roll (but note, Cha only gets a bonus/penalty of -2 to +2, not -3 to +3 like other ability scores).
So, if the party acts friendly and has a charismatic character who speaks that language, they could get up to a +4 bonus on the 2d6 roll, which is huge. In such cases, the worst possible result is a 6, which is uncertain. Then on the next roll, the worst possible reaction is Negotiate, and on the third roll then the worst reaction is that the monsters leave. If the initial reaction roll is 8 or higher with both of those bonuses, the monster is immediately friendly!
Of course, the opposite is true. If the PCs can only speak to the monsters through a low Cha character (-1 or -2), and make hostile, threatening gestures, then there's little chance of a friendly reaction and a high chance of combat ensuing. But if the only character who speaks Harpy has low Charisma, character actions can make up for the deficit and leave you with a standard roll.
And people say Charisma is a dump stat in this edition! Well, if you play hack-and-slash, it is. But it shouldn't be and wasn't intended to be.
We get a small section here describing how to handle negotiating with monsters. If the monster thinks the PCs look powerful, it may make offers of friendship or treasure to keep the PCs from attacking. If it thinks the PCs look less powerful, it may try to extort treasure or food to keep it pacified. And we've got a reminder here that Chaotic monsters usually won't keep their bargains, and Neutral monsters only will as long as it seems advantageous to them, while Lawful monsters will always keep their bargains.
It's telling that Frank says here:
Reactions can make the game much more fun than having fights. With some careful thought, a good DM can keep everyone interested and challenged by the situations that can arise. Remember that no creature wants to get killed, and if the party looks or acts fierce, many creatures can be scared away or forced to surrender -- although large and tough monsters probably won't scare very easily. (p. 23)If anyone ever tells you that TSR D&D or OSR games are just nothing but orc-and-pie dungeon delve combat simulator games, have them go read this section of this book. Then ask them what they think.