When characters are climbing in a difficult or tense situation, the referee may require an ability check against Dexterity.
Very steep or sheer surfaces are normally impossible to climb without specialised equipment. Some characters may have class abilities which allow them to attempt to climb such surfaces unaided.
Characters will usually want to bring a source of light with them on underground expeditions. Typical light sources enable normal vision within a 30’ radius.
All non-human monsters and many demihuman races have a special kind of vision that allows them to see in the dark. This is called infravision.
Heat tones: Characters who have infravision can see the heat energy that radiates off of living things. Generally, living things will be visible as bright tones, while cool items are grey and very cold objects are black.
Reading: It is not possible to read in the dark with infravision, because fine detail cannot be perceived.
Range: Infravision works within a limited range (60’ for monsters, unless specified otherwise in a monster’s description).
Disruption: Infravision only functions in darkness. Visible light (normal or magical) and large heat sources will disrupt it.
Characters or monsters that carry a light in a dark environment are usually unable to surprise opponents, because the light gives their presence away.
Falling from a height onto a hard surface inflicts 1d6 damage per 10’ fallen.
Characters can confidently follow trails, roads, and other well-known landmarks without fear of becoming lost. Likewise, travelling with a reliable guide prevents becoming lost. However, when travelling through untracked, open regions, it is easy to lose direction.
The chance of the party becoming lost depends on the type of terrain being explored.
If the party becomes lost, the referee will decide which direction they are actually travelling in. One option is to pick a direction only slightly off course. For example, if the group intended to go south, they are actually headed southwest or west.
It may take some time for a lost party to realise that it is moving in the wrong direction.
If characters go for a full day or more without food or water, the referee may begin to apply penalties to attack rolls and movement rate, require more frequent rests, or even begin to deduct hit points (in extreme cases).
Movement rate: Characters move at half their normal movement rate when swimming.
Who can swim: It is assumed that every character knows how to swim, unless there is some obvious reason why a character could not have learned.
The circumstances in which drowning is a risk—as well as the chance of drowning— are judged by the referee.
Example circumstances: Swimming in treacherous water conditions, swimming while wearing armour or carrying heavy or awkward items, fighting in water.
Example chances of drowning: A character swimming in rough waters while wearing heavy armour and carrying a heavy load may have a 99% probability of drowning. A character in the same waters but wearing light armour and carrying a light load may only have a 10% probability of drowning.
Besides the monsters specifically placed in certain regions of a dungeon or wilderness, PCs may randomly encounter monsters on the move between areas. These are known as wandering monsters. See Dungeon Adventuring, p210, Wilderness Adventuring, p212, and Waterborne Adventuring, p214 for specific details.
Frequency: The referee should roll periodically to determine whether a wandering monster is encountered. The frequency of checks depends on the type of area being explored.
Chance: When a wandering monster check is made, the chance of a random encounter is usually 1-in-6. This chance may vary, depending on the type of area being explored (e.g. dungeon region or level, type of wilderness terrain).
Monster type: Each area should have its own table of wandering monsters, which the referee rolls on when an encounter takes place.
Noise or light: If the party is making a lot of noise or carrying bright light sources in a dark environment, the referee may increase the chance of wandering monsters being encountered.
Hiding: If the party rests quietly in an out-of-the-way location, the referee may decrease the chance of wandering monsters being encountered.