First we discovered that the Earth is round.
Then we discovered that it’s hollow.
A Dieselpunk Adventure into a Hollow World [ edit ]
Like many Dieselpunk games, Hollow Earth Expedition starts with our normal, mundane world, in the 1930's ... but then adds a twist, in this case a conspiracy to hide the fact that our world is not in fact solid, but instead holds an undiscovered second world inside of it. In the game characters first struggle to find an entrance to this mythical inner world, and then work to explore it's strange primitive people and fantastic creatures.
To be fair, Hollow Earth Expedition (or "HEX" for short) is not a heavily dieselpunk, with more of a pulp/exploration focus. However, it does include some strong dieselpunk elements (eg. drilling machines, jet packs, and robots), and the setting easily lends itself to GMs adding any further "weird science" or dieselpunk elements they may desire.
Hollow Earth Expedition, First Edition - Rules SummaryCollapse
Character Creation [ edit ]
To create a HEX character you first select an "archetype", such as Adventurer, Celebrity, Occultist or Reporter. Archetypes are similar to classes, but have far less in-game impact; the rules suggest that you "think of
them as concepts and stereotypes for you to build upon,
not as templates of skills and abilities."
Next, the player selects their character's driving goal. Every character must choose one, because it takes a strong motivation for a person to adventure all the way inside the Earth itself, and the GM can reward characters for role-playing their motivation with "style points". Motivations are limited by archetype, so for instance an Adventurer, Celebrity or Reporter might have Fame as a motivation, but not any other archetype.
Next the player spends 15 points (on a one-for-one basis) to purchase their six primary attributes. Every attribute has a minimum of one point and a maximum of five. These attributes are almost identical to those in Dungeons and Dragons, except that Constitution and Wisdom have been replaced with Body and Willpower.
After the primary attributes are determined a number of secondary/derived attributes are calculated based on the primary attributes. These include the character's size, move, initiative, and stun/health.
Next the player selects from among 30 skills for their character (eg. Animal Handling, Investigation, Melee, or Stealth). Skills aren't limited by archetype, although the game encourages you to pick skills that match, and each character gets 15 points to spend (max 5 in any one skill).
Characters can also "specialize" in a skill by spending half a skill point. For instance if a character wanted to better with shotguns than other firearms they could spend half a point to specialize their firearms skill. Characters can only have one specialization in each skill (at creation), and it gives them an extra die when the specialization is applicable to the roll.
Talents and Resources
Each character gets either a single Talent (unique ability) or Resource (connections/wealth). Talents include things like being charismatic, being able to fight blind, being extra-large, or simply being lucky, while resources include things like artefacts the character has collected, mentors or followers, or just plain old wealth.
Some talents and all resources can be purchased multiple times to increase their effect: for instance, a single level of wealth provides a $250/month stipend, while a second level instead provides $500/month, and a third level increases the amount to $1000/month.
Each character may optionally choose to start with a Flaw. Whenever that flaw negatively impacts the character they earn a style point as a result (and also start the game with an extra point). Flaws include being absent-minded, disfigured, mute, or unlucky.
Starting Experience Points
Somewhat unusually for an RPG, HEX gives characters 15 experience points to spend at character creation. The character can spend these points to improve their attributes/skills/specializations, or they can spend all 15 to purchase a single extra talent or resource.
Core Mechanics [ edit ]
Hollow Earth Edition has a somewhat unique system: as a "d2" system every die roll is essentially just a coin flip: an even result indicates a success, while an odd result indicates failure.
To perform an action the player first determines the type: standard, extended (ie. a long-term action, like repairing a vehicle), opposed (an action that another character is trying to stop) or reflexive (an opposed action made in response to another's action).
Next, the GM then sets the target number, from 1 (for an easy task) to 6 (for a nigh impossible one), and the player rolls their dice pool trying to achieve that many successes. Their dice pool is equal to their relevant attribute plus relevant skill, plus modifiers for other factors (eg. a bonus if they are using a good set of tools, or a penalty for trying to make the check in the dark)
Taking the Average
To save unnecessary rolls and keep the game moving, if the character's dice pool is greater than or equal to twice the target number (eg. 4+ dice for a TN of 2) .... or in other words, if the character would succeed on an average roll ... the character succeeds automatically.
Degrees of Success and Failure
Whether the character succeeds or fails, the amount that they succeeded/failed by is used to determine how well/poorly the action failed. This is particularly relevant in combat, as additional successes on the roll result in increased damage.
If a roll doesn't have a single success (ie. even number) that roll is considered a critical failure, and the GM determines an appropriately negative result for the character.
Characters can earn style points through good role-playing, particularly with their Motivation and/or Flaw(s). These points can then be spent to purchase extra dice for critical rolls (as well as for other benefits, such as a temporary increase to a talent' level or to reduce damage taken).
If a character is feeling lucky they can opt to get two bonus dice ... at the cost of adding one to the TN (statistically the two balance out on average, so this essentially just introduces extra randomness to the roll, adding to the game's pulpy feel). A player can get up to ten dice this way, but they cannot "take the average" if they do.
Combat [ edit ]
Each character has an initiative score (derived from their Dexterity + Intelligence), which they roll to determine their initiative order. This roll is repeated every turn (six seconds) of combat, and higher initiative rollers can hold their action to wait and go later.
Each turn a character can take a single attack, defense, and move action. Attacks and movement are performed on the character's turn, while defenses are reflexive actions (when attacked). Characters can also Sprint or take a Total Attack or Total Defense action to forego an action type in exchange for a bonus to the main action.
There also a variety of actions for specific types of combat actions, ranging from aiming, to charging, to attacking cautiously, to tripping .
To attack the GM first determines modifiers for the target's size, range, visibility, and wound penalties, and then the attacker makes a roll using the appropriate melee or ranged attack skill (eg. firearms). The defender then makes an opposed defense roll, and if the attacker beats the defender's roll they hit (ties go to the defender).
Each weapon has a fixed Damage Rating, and deals either lethal or non-lethal damage. For example, a punch has a DR of 0 non-lethal, while a gatling gun deals 4 lethal damage. For every extra success on the attack, the attacker adds one to their weapon's damage.
Each character has a Health score (their body + willpower + size) which is essentially their hit points: when reduced below zero the character falls unconscious, and at -5 Health they die.
Damage can also have other effects. If a single hit's damage exceeds the character's Stun (ie. body) score they lose a turn, and if they take more than double that score they are instead knocked out. Similarly if an attack's damage exceeds a character's Strength score they are knocked back or (if it exceeds 2x Strength) knocked down.
A "Finished" Game [ edit ]
Aggregated Review Scores
|Source||Average Score||# of Reviews||As Of|
|Amazon||4.7 / 5||47||3/2/2022|
|Drive Thru RPG||4.4 / 5||60||1/26/2022|
|Good Reads||4.07 / 5||75||1/26/2022|
|RPG Geek||7.59 / 10||79||1/26/2022|
Unfortunately HEX's publisher (Exile Games) no longer exists, and it's creator has moved on to other projects (although the game's core Ubiquity rules system is still used in new games, notably the "Leagues of ..." games from Triple Ace Games). However, before it ended HEX published a large number of supplements (plus fans also released a number of unofficial supplements), and they are still available on Amazon, Ebay, or Noble Knight.
As a result, it's still very possible for a GM to acquire HEX, as well as tons of great supporting material, but the real question is: is it worth the trouble? Well, one answer is that despite being an independently published (and now discontinued) game, HEX managed to rank 137th on RPG geek ... out of all RPGs/editions!
RPG Geek generally has the harshest reviews, and even so 79 critics on the site gave the game's core rulebook an average score of 7.59 / 10. Other sites were even more favorable: GoodReads (with 75 ratings) gave a 4.07 / 5 average, while Amazon (with 45 reviews) gave an even higher 4.8 / 5 average.
The only real negative comments largely focused on the game's world (the non-hollow part) being a bit undeveloped ... although reportedly the "Secrets of the Surface World" supplement helped remedy this concern for some. Also, some simply didn't like the "pulp" setting of the game, and an occasional reviewer felt that the d2 Ubiquity system was too simple for their tastes.
While the pulpy setting and Ubiquity system (with it's extremely simple die rolls) may not appeal to everyone, the vast majority of reviewers reported loving both the rules and world of Hollow Earth Expedition. If the idea of a campaign where the players race Nazis to explore a secret world of dinosaurs and primitive peoples (with dieselpunk giant drilling machines, jet packs, and more) sounds fun, then you need to check out Hollow Earth Expedition.