GM's 101

Here are just a few tips to help you run a game of Hypertellurians.

Running the Game

Bring the Fun

Don’t hide the adventure (see also “No perception checks”), and don’t wait too long for your characters to figure out cryptic clues. If you don’t want to reveal the answer to a mystery directly, keep up the pace by throwing in an unexpected complication instead. Pacing is important; you don’t have to string action after action, but when you see your players getting distracted from the game, throw them a curveball. Putting the characters into dangerous positions is your job, just make sure they’re fair and can result in character rewards and fun at the table.

Fail Forward

Shield maiden roaring a battle cry
‘Shield Maiden’ by Jonny Gray

Don’t stop your adventure in its tracks because of a failed roll. Add an extra complication instead. If you do this right, your players will actually look forward to failing the odd roll.

For example, your characters are running towards a rocketship that’s about to launch, and you ask for agility checks to jump onboard in time. One of them fails the roll. Instead of leaving them stranded, they make the jump but one of the pursuers managed to grab onto their ankle, and now they have company. Or else, leave the character stranded but show how they’re taken captive by the pursuers, so the party comes back later. And when they do, perhaps they discover that the captive character has in fact become the new king of their erstwhile pursuers. (Tell the player that in private after they fail the roll, and watch them smirk in front of the others who made the roll.)

An easy way to remember to fail forward, is to say “let’s see how well you do” when asking for a roll, instead of “let’s see if you succeed.”

Say Yes

Nothing is more disheartening to a player than telling them their character can’t attempt (!) to do something. Ask yourself why you’d want them to stop from doing something. Are they trying to powergame, cheat, or take the fun from other players? If not, let them do it. And even if it’s something you think their character shouldn’t be able to do, or should have consequences, remember the two amazing aces in your sleeves: “Yes, and…” and “Yes, but.”

No perception checks

Having the players roll to see if they spot the adventure sucks. Tell your characters what they see and keep quiet about surprises. The only time to ask for a roll is if they’re explicitly searching for something that is actively trying to remain hidden. And even then, ask yourself if it would derail the fun if the thing stayed hidden. If yes, don’t roll, just have the most observant character—or the player who has interacted least so far in the session—spot it.

Know your players

And know their characters, and make everything about them. Weave their back- or origin stories into your adventures, and have mysteries be related to them or their friends or families, or the items they have looted so far. Give a starting character a mysterious heirloom item and make it central to one of the adventure. Cycle your character focus so that no player feels left out. Know their character’s powers and engineer situations where those powers can become useful.

Only you know whether your players prefer fights, roleplaying discussions with NPCs, or solving mysteries. Create scenes that satisfy as many of these as possible. And create scenes that are fun for you too!

Beware of overlong player planning

You’ve set out a goal and your players have taken the bait, and are setting out to plan how to achieve it. An hour later, they’re still discussing the pros and cons on their various strategies. Sound familiar?

Avoid having your pace interrupted or your atmosphere dissipate by unnecessarily long or involved planning. Interject phrases like “you’ll never know until you try, or go and see,” and “from your past experience, you think you’re up to this.” If necessary, force a decision onto a likely character: “Your Royal has never let you down with these kinds of strategic decisions, you should follow her lead.” And if all else fails, liven things up by throwing in a random encounter or complication.

Making it Hypertellurians


Hypertellurians aims to depict a “raypunk”, “swords and sandals” strand of science fantasy. The core rules already touch on this with regards on what phrases and terminology to use. Where this becomes a little trickier is when you switch worlds, as this game is wont to do. You might go from a dying, dystopyian world to a sillier, gonzo one. In this case, try to “reset” your tone via the framing device that links your adventures. It’s ok to switch tone during a campaign, as long as you regularly bring it back in line with the base tone of heroic, mysterious exploration.

Even when you cycle from fantasy to science fiction and beyond, you can keep a sense of continuity by taking care of the language you used to describe the world. If you stick to ray emitters, automatons, and flaming swords, instead of lasers, robots, and lightsabers, you’ll have tone consistency across worlds.

Hand out Wonder

Wondrous actions and characters’ proficiencies all cost wonder, and these are the main ways for the players to get advantage on checks. Getting advantage is the prime method for increasing a character’s odds of success, so the player will strive for it often, and that’s ok.

It’s your job to tell them when they discover or experience something amazing and hand out appropriate amounts of wonder. Do not forget to do this. Do it for small things, like a particularly amazing (combat) action, or fabulous art, as well as big things, like laying eyes onto the hovering tree village for the first time.

Crazed looking berserker
‘Berserker’ by Jonny Gray

Magic, spell tomes, spells

In Hypertellurians, any character can technically be a wizard. All they need is to find spell tomes, and have a high enough relevant ability to soak the damage for casting the spells. One spell tome should generally contain a single spell, and take up 1 inventory slot. Like archetype or general advances and powers, spells should generally inflict ability damage onto the caster—this is the game’s way of limiting their use. For spells Mind damage is likely appropriate, but don’t be afraid to mix it up, as long as it makes sense. Casting a spell requires wielding the spell tome in question, or else, having learned the spell via an advance.

The game encourages you to invent new spells, but it’s just as easy to adapt existing spells from most RPGs, if you follow these guidelines:

  • determine if it’s a minor, medium, or major spell
  • casting the spell should cost ability damage commensurate to the spell effect
  • lean towards interesting, somewhat open-ended spell effects rather than simple numerical damage dealers

If you are looking for spell inspiration beyond standard, established spell lists, consider the following sources:


All you need for an enemy, stat-wise, is the BAM agility scores, their equipment (especially armor and weapons), and—if applicable—one or two powers. Then, determine their hit points, and you’re ready. In time, specific examples will no doubt appear on the blog.


For most enemies, a 13 in their strongest ability, and 10 in the others works fine. For mooks, consider making them easy to hit (Agility 8) with few hit points to let the characters plow and cleave through them. Give them a Brawn of 13, and they’re still dangerous. For bosses, you might go as high as 14 or 15, but use it sparingly. Instead, give them the equivalent of the Hard Knocks advance, and/or an interesting power or two.

Hit Points

In current playtests, 3 hit points per Hit Dice has worked pretty well. Add a few extra to bosses if necessary, and chalk it up to them having Toughness I, II, or III.

Exotic woman with giant snake
‘Snake Queen’ by Dean Spencer


With a slotted inventory system, the amount of slots a reward takes up determines how valuable it is, on top of any other intrinsic value. Coins and gems can go into a single “coin pouch” slot within reason, for example. Armor and weapons add up quickly. And for a wizardly character, their collection of spell tomes might soon strain against the low number of slots due to their likely unfavored Brawn score. Therefore a spell tome containing more than one spell is a much greater treasure. The same is true of any item that might award additionals slots, such a bag of holding. However, such items should probably be avoided, in favour of carts, or henchmen, the more traditional methods of dealing with loot. When slot management is trivialized, it becomes a chore rather than a fun subsystem that encourages meaningful loot choices and quick potion quaffing.

Think of the inventory slots system as a preparation step before the adventure, where the player determines what their character brings along and what they leave at home.

Gold and gems remain a viable reward, even in a game spanning multiple worlds of varying cultures and technological advancements. But in order to retain value, you should introduce either an easy means converting the various denominations into local currencies, or merchants accepting of all of them. For this you might use a trading hub, perhaps in your framing device’s base of operations, for example.

Framing devices

One thing all Hypertellurians games should have in common is a means of crossing between worlds, of travelling from one dimension of the Ultracosm to another. This doesn’t have to be in the characters’ power; it could be an NPC in charge of it.

Here’s a handy table to get your creative juices flowing.

# The characters are… traveling the Ultracosm to… via…
1 escaped prisoners collect magic items for their benefactor who broke them out of their various prisons portals in the benefactor’s demesne, the Root of Worlds
2 members of the Battle Sisters of the Merciful Sepulchre spread the holy word the ritually powered, Mobile Battle Shrine
3 mercenaries rid it of evil in whatever form it comes ancient, wrist-mounted artifacts that only work when brought together
4 perpetual students of a wizard school unlock the secrets of existence powerful rituals
5 exiles from different worlds test their mettle a tome detailing the weak spots in the fabric of space and time between dimensions
6 a group of poets, epicureans, and bon-vivants sample each single one of its delights an incomprehensible but marvellous metal sphere, portalling them seemingly at random
7 identical souls, but from different worlds or times escape the relentless evil that follows them predetermined ultracosmic breaches
8 slaves satisfy their owner’s whims astral projection
9 evil overlords expand their empire a fortress of steel and spikes powered by the lamentations of its prisoners
10 spoilt princes and princesses win a dare their father’s purloined magical carriage


Hypertellurians was specifically conceived as a means to stitch together the multitude of adventures, settings, and modules in the author’s library, all the way from D&D and Pathfinder to OSR, DCC, LotFP, Trilemma, and beyond.

For one-shots, you can’t go wrong with Michael Prescott’s fantastic adventures. Literally every book published by Lamentations of the Flame Princess, or the wider oeuvre from that community works incredibly well, as do the Dungeon Crawl Classics modules. If you want to write your own, the Dungeon Alphabet is a great starting point.

The OSR community has a number of excellent hex crawls out, like the Dolmenwood series, Fever Swamp, Isle of the Unknown, and Hot Springs Island.

Now go, and explore the Ultracosm!