---
title: 'HOSR Core Rules: Adventuring'
description:
date_pub: 2023-04-26T23:02:00-04:00
section: rules
content_type: feature
short_code: uha
---
[[toc]]
### Ability Checks
Simple tasks are assumed to succeed. If the task is dangerous or complicated, roll the dice for an Ability Check.
- For most checks, roll a 20-sided die (d20) **at or over** the specified Difficulty Class (DC) for that ability.
- For harder tasks, add 1-4 to the DC before the die is thrown.
| Ability
Score | Roll
Bonus | Base DC |
| ^^ | ^^ | ^^ |
| :-: | :-: | :-: |
| 18 | +3 | 6 |
| 17 | +2 | 6 |
| 16 | +2 | 7 |
| 15 | +1 | 7 |
| 14 | +1 | 8 |
| 13 | +1 | 9 |
| 12 | +0 | 9 |
| 11 | +0 | 10 |
| 10 | +0 | 11 |
| 9 | +0 | 12 |
| 8 | -1 | 12 |
| 7 | -1 | 13 |
| 6 | -1 | 14 |
| 5 | -2 | 14 |
| 4 | -2 | 15 |
| 3 | -3 | 15 |
[Ability Check Roll Bonus and DC]
- Some results are special:
- A natural 20 represents a critical success: the check automatically succeeds, and often includes a bonus for the roller.
- A natural 1 is a critical failure: the check automatically fails, and the attempt often causes an additional complication or challenge for the roller.
### Exploration Procedure
The general steps to take when exploring (dungeon, wilderness, etc.)
1. **Setup**: Referee describes the situation
2. **Marching Order**: Party determines general exploration process, including direction of travel and speed.
3. **Complication Check**: Referee rolls the complication die to see what effect it has.
4. **Actions / Responses / Complications**: Party declares actions, referee describes the results (and any complications).
5. **End Turn / Watch**: When the party has gone far enough or combat has completed, the (dungeon) turn or (wilderness) watch ends.
- Dungeon: 240'
- Wilderness: 6 miles
6. **Repeat**: Return to step 2 and repeat until the adventuring ends.
#### Complication Check
Roll 1d6, ignoring results of 4+ for the first 4 turns in a session (or since they last occurred).
1. **Encounter**: Wandering creature, social encounter, or some other random interaction.
2. **Signs / Portents**: Indications of possible encounter nearby - could be a clue, monster tracks, etc.
3. **Locality**: Some environmental or external event that affects the PCs - water rises, the assassin gets closer to the target, doors lock behind the party, etc.
4. **Exhaustion**: Take a rest turn (short rest) or (additional) -1 to all rolls until you do.
5. **Light Source**: Torches go out, lanterns go out every third time.
6. **No Complications**
#### Darkness
- -4 to attack when unable to see
- Candles light 10' radius
- Torches / lanterns light 30' radius
#### Infravision
- Can see heat tones, even in the dark.
- Usually works to 60'.
#### Listening at Doors
Spend a minute listening at a door to have a base 1-in-6 chance of hearing a noise.
- Referee makes this roll.
#### Opening Doors
- Locked Doors can be picked or broken.
- Picking a lock takes 1d6 minutes.
- Stuck Doors can be unstuck or broken.
- Doors always break on a 1. Failure can affect stealth / surprise.
| STR | Unstick | Break |
| :---: | :-----: | :----: |
| 3-8 | --- | 1-in-6 |
| 9-12 | 2-in-6 | 1-in-6 |
| 13-15 | 3-in-6 | 2-in-6 |
| 16-17 | 4-in-6 | 3-in-6 |
| 18+ | 5-in-6 | 4-in-6 |
[Forcing Door Chances]
##### Exhaustion
- Exhausted creatures attack and deal damage at -2, and get -2 to their AC.
- Exhaustion can be cleared by resting for 30 minutes (3 turns).
#### Other Hazards
- Fall damage is 1d6 / 10'.
#### Swimming
- Creatures are assumed to be able to swim at 1/2 their normal movement speed.
- Unless the creature is just floating, a STR or CON check is required every turn (10 minutes).
- For creatures carrying heavy loads or wearing metal armor, this check is required very combat round (10 seconds).
- Failing this check results in a loss of 1 HP, and the check must be immediately attempted again.
- The third failure indicates the creature begins **drowning**``.
#### Drowning
- Each combat round, a drowning creature must **Save vs Death** or take 1d8 drowning damage.
- When a drowning creature is rescued, it becomes exhausted.
- Once the exhaustion clears, the creature gains back any HP lost to drowning.
#### Urban Navigation
To navigate to a location in a busting city, make a Reaction Roll (2d6) + CHA mod + INT mod.
- Modify roll in friendly, dangerous, or especially alien areas.
- Navigation time includes time spent reading maps and getting directions, as well as any eating or rest stops needed along the way.
- Roll random encounter checks each hour
| Roll | Result | Time Spent |
| :--: | :-------: | :--------------------: |
| 2 | Failure | Waste day searching |
| 3-5 | Wandering | Arrive after 2d4 hours |
| 6-8 | Success | Arrive after 1d6 hours |
| 9-11 | Fortunate | Arrive after 1d4 hours |
| 12+ | Direct | Arrive after 1 hour |
[Urban Exploration Results]
#### Wilderness Exploration
- Distances and non-magical ranges are tripled (yards rather than feet).
- Areas of breath weapons and spell effects are still measured in feet.
**Flight**
- Unless stated otherwise, flight distance is double that of overland travel.
- Flight speed is not affected by terrain.
- Winged beasts may be used as **mounts**, carrying riders or cargo based on the mount's HD:
- 3 HD: May carry a creature 1/2 the size of a humanoid.
- 6 HD: May carry a creature the size of a humanoid.
- 12 HD: May carry a large creature (ex: horse)
- 24 HD: May carry a huge animal (ex: elephant)
**Overland Travel**
- The distance in miles that a character can travel overland in a day (16 hours) under normal conditions (and clear terrain) can be determined by multiplying their base movement rate by .6 (or 3/5).
- 10' / round => 6 miles / day
- 20' / round => 12 miles / day
- 30' / round => 18 miles / day
- 40' / round = 24 miles / day
- Some terrain affects overland speed while traveling through it:
- Maintain roads: Increase speed by 50%.
- Hilly, wooded, or desert terrain: Decrease speed by 33%.
- Swampy, mountainous, or jungle terrain: Decrease speed by 50%.
- Characters engaged in a forced march can increase their travel speed by 50%, but must rest for a full day or suffer exhaustion (-1 to all rolls).
- Characters must rest 1 day for every 6 days traveling or suffer exhaustion (-1 to all rolls, cumulative for each additional day without rest).
**Sight**
Characters can usually see 3 miles around (in clear terrain).
- Range of sight may vary based on terrain (ex: less in wooded area, more on an overlook).
### Encounter Procedure
1. **Check Stealth**: Referee rolls for stealth, if applicable.
- Each side that's being relatively stealthy (quiet, douses torches, etc.) has a base 2-in-6 chance of not being spotted.
- Parties carrying an active light source typically can not have stealth.
- If only one side has stealth, they may usually make a free attack (or can pass unnoticed).
- If all sides have stealth, they miss each other.
2. **Determine Distance**: Referee determines how far away the characters are from the encounter.
- Often determined by the nature of the encounter itself, but may be determined randomly:
- Dungeon: 2d6 x 10'
- Wilderness: 4d6 x 10 yards (or 1d4 x 10 yards if either side is surprised).
3. **Roll Initiative**: Each side that has stealth rolls 1d20, highest roll moves first.
4. **Choose Actions**: Each side decides how they will respond in initiative order, and the encounter proceeds.
- Players decide how their characters will act.
- Creature actions are often determined by the nature of the encounter itself, but may be determined randomly.
- If creature / NPC reaction isn't obvious, roll 2d6 (+ CHA modifier, if someone tries to communicate).
| 2d6 | Result |
| :-: | :---------: |
| 2- | Attack! |
| 3 | Hateful |
| 4 | Leery |
| 5 | Rude |
| 6 | Aloof |
| 7 | Uncertain |
| 8 | Confused |
| 9 | Indifferent |
| 10 | Cordial |
| 11 | Amiable |
| 12+ | Friendly! |
[Reaction Table]
| CHA | Mod |
| :---: | :-: |
| 3 | -3 |
| 4-5 | -2 |
| 6-8 | -1 |
| 9-12 | +0 |
| 13-15 | +1 |
| 16-17 | +2 |
| 18+ | +3 |
[Charisma Modifier]
5. **End Turn**: Once the encounter has played out, the turn ends.
- Each encounter is assumed to take at least one full turn to complete.
- This includes time to regroup, bind wounds, clean weapons, rest, etc.
#### Typical Actions
While any action is possible, the following actions are the most common:
- **Combat**: If a side attacks, casts a spell, or makes a tactical movement, [combat](./combat.html) begins.
- **Evasion**: If a side decides to flee, another side may decide to pursue.
- **Talk**: One side may attempt to communicate with the other(s).
#### Evasion
Any side that wishes to avoid an encounter may attempt to flee.
- Only possible before combat begins.
- Each opposing side declares whether or not they want to pursue.
- Players decide freely if they wish to pursue fleeing creatures.
- Referee decides whether creatures pursue fleeing PCs (based on circumstances or roll).
- If all opposing sides decide not to pursue, the evasion attempt automatically succeeds and the encounter is avoided.
- If an opposing side decides to pursue, the chance of evading depends on the surrounding environment.
### Advancement
As the adventures continue, treasure is acquired and creatures are vanquished, all adding to the PCs XP total.
- Each standard coin worth of treasure gained is worth 1 XP, and each creature has an XP value awarded for beating them (one way or another).
- The total XP are then divided amongst the PCs and any hirelings they have (at 1/2 share per hireling).
- Players running multiple characters gets a full share for their first PC and a half-share for the second, although they choose how to distribute the points.
- Referees may increase the derived value arbitrarily.
- Once a PC acquires enough XP, they go up to the next level in their class.
#### Upon Gaining a Level
When a PC increases their level, the following actions may be performed:
- Roll a hit die (based on the PC's class), and add it to their maximum hit points.
- 1s and 2s may be re-rolled.
- Alternatively, roll the next die step down and add 2.
- Their player may pick one of the PC's abilities, and roll 3d6.
- If the resulting roll is higher than the ability score, increase the score by 1.
- Check the PC's [class](/classes/index.html) and [race](/races/index.html) to see if any new abilities are gained.
### Encumbrance
Characters can carry a number of "Important Items", based on their Strength (STR).
- Items can be carried **At Ready** or **Packed**.
- "At Ready" items may be grabbed and used without delay.
- Packing or unpacking items takes 1 turn.
- Characters can carry a number of at-ready items up to their Strength (STR), to a minimum of 7.
- Additionally, characters may carry a number of packed items up to their Strength (STR), to a minimum of 7.
- Leather armor counts as 1 item, mail counts as 2 items, plate counts as 3 items.
- 2-handed weapons count as 2 items.
- 100 coins or gems count as 1 item.
- Carrying more ready or packed items than allowed can be done, but movement is halved (or worse).
- Carrying more than twice the allowed number of ready or packed items reduces movement to 0.
### Health, Damage and Dying
The state of a character's health is determined by their number of hit points (HP).
- Starting HP is usually determined by class and level.
- The type of Hit Dice to throw is determined by class
- The number of Hit Dice to throw is determined by level.
- Re-roll any 1s or 2s.
- Modify the rolled value of each die by CON as below:
| CON | Mod |
| :---: | :-: |
| 3 | -3 |
| 4-5 | -2 |
| 6-8 | -1 |
| 9-12 | +0 |
| 13-15 | +1 |
| 16-17 | +2 |
| 18+ | +3 |
[Constitution Modifier]
- When damage is taken, HP is lost.
#### Dying
- Monsters and NPCs usually die at 0 HP.
- PCs at 0 HP (or lower) make a **Saving Throw vs Death** at the end of each round of combat.
- On success, stabilize at 1 HP (no need to continue saving vs death), but can't fight and can only move 1/2 speed until treated or healed.
- On fail, lose 1 HP to blood loss and try again next round.
- At -(level) HP (or lower), save or die.
- PCs should never die from a single bad roll, but two bad rolls is enough.
#### Healing
- After each long rest (8+ hours of sleep), regain 1 _hit die (HD)_ worth of HP.
- Once per day, take a short rest (10 minutes) and eat a ration to regain 1 HD worth of HP.
- Certain potions of healing can also be used:
- Drinking a healing potion restores up to 1d6+1 HP.
- Imbibing a potion of greater healing restores up to 2d6+2 HP.
- Quaffing a potion of supreme healing restores up to 3d8+3 HP.
### Knowledge
**Identifying (Magic) Items**: Spellcasters get INT check.
**Medical Treatment**: INT check, success stabilizes dying characters and restores their ability to move and fight.
- Can't be used on oneself.
### Languages
- Anyone who speaks a language can understand other related lanuages (ex: dialects) with a successful INT check.
- Some orders and guilds (especially those that engage in illegal / immoral acts) may teach their members secret or otherwise coded language.
- The following lists of languages are not all-inclusive.
#### Alignment Languages
Assumed to shared by all (intelligent) members of a given alignment.
- **Chaotic**: Alignment language of chaos.
- **Lawful**: Alignment language of law.
- **Neutral**: Alignment language of neutrality.
#### Class Languages
Most class languages are secret, known only to members of their class, and often include coded terms and/or physical motions (hand waves, knocks, etc.).
- **Assassin's Cant**: Secret (and coded) language known to all thieves.
- Dialects are based on different guilds.
- **Corsair's Cant**: Secret (and coded) language spoken by all Corsairs.
- Dialects are based on different ship / locations.
- **Druidic**: Secret language spoken by all Druids.
- **Thieves' Cant**: Secret (and coded) language known to all thieves.
- Dialects are based on different guilds.
#### Racial Languages
- **Aerian**: Native language of air elementals, dialect of elemental.
- **Angelic**: Native language of angels (law elements), dialect of both lawful and elemental.
- **Aquon**: Native language of water elementals, dialect of elemental.
- **Demonic**: Native language of demons (chaos elements), dialect of both chaotic and elemental.
- **Doppleganger**: Native language of dopplegangers.
- **Draconic**: Native language of most intelligent reptilian races (kobolds, troglodytes, lizardfolk, dragons, dracokin, etc.).
- **Duncommon**: Native language of those that dwell deep underground and other dark places (Drow, Medusa, etc.).
- **Dwarfish**: Native language of dwarves.
- **Elemental**: Spoken by all elementals, each subtype has their own dialect.
- **Elvish**: Native language of elves, dialect of faerie.
- **Faerie**: Native language of the fae, usually divided into 2 dialects:
- **High Faerie** Spoken in the ruling courts of the Faewolde.
- **Low Faerie**: Spoken everywhere else in the Faewolde.
- **Farspeak**: Language of the far realms.
- **Gargoyle**: Native language of gargoyles.
- **Giant**: Native language of giants.
- **Goblinoid**: Native language of most intelligent goblinoid races (boggarts, bugbears, goblins, hobgoblins, etc.)
- **Gnollish**: Native language of gnolls.
- **Gnomish**: Native language of gnomes.
- **Greyok**: Native language of several intelligent mammalian animalkin races (Elekin, Hippokin, Rhinokin, Taurokin).
- **Halfling**: Native language of halflings.
- **Orcish**: Native language of ogres and orcs.
- **Pyrean**: Native language of fire elementals, dialect of elemental.
- **Strallan**: Native language of the Stral and official language of the Stral Empire.
- **Terrun**: Native language of earth elementals, dialect of elemental.
| INT | Spoken Languages | Read? |
| :---: | :--------------: | :---: |
| 3 | Native (broken) | No |
| 4-5 | Native | No |
| 6-8 | Native | Basic |
| 9-12 | Native | Yes |
| 13-15 | Native + 1 | Yes |
| 16-17 | Native + 2 | Yes |
| 18+ | Native + 3 | Yes |
[Languages Known]
### Perception Checks
Generally, perception can be checked by rolling highest of INT or WIS.
### Size
A creature's size is usually defined by one of the following categories based on its height and/or weight:
| Size | Max Height | Control Radius |
| :--------: | :--------: | :------------: |
| Tiny | 2' | 2.5' |
| Small | 4' | 5' |
| Medium | 8' | 5' |
| Large | 16' | 10' |
| Huge | 32' | 15' |
| Gargantuan | 32'+ | 20'+ |
[Creature Sizes]
### Time
Time is often represented at different scales:
- A combat round is 10 seconds long.
- An exploration turn takes 10 minutes.
- A watch takes 4 hours.
- A long rest takes 8 hours.
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