A micro-review

A system for Tony Dowler's perfectly compressed micro-dungeon maps?

Try the ultra-concise Deeds & Doers.

Only players roll – 'to do' – when there is a significant risk.

The DM applies injuries and conditions with judgement, not hit points.

A game you can hold in your head.

Fantasy dungeons, sword and sorcery, all by suggestion. Pick your source; then where, who, why.

Here's a D20 adventure game

Basics and characters

Write down your character name and then a description. Make it concise or detailed. Include some skills or a calling/profession.
Roll 2d6 and add six. These are you Health Points, or HP. Write them in near the top. Hits wear them down. When you have no more HP, you cannot take a hit without serious consequences.

Rolls

Further down, you have three rolls: Fighting, Skill, and Magic. These have a base value of 6+.

For a random character, roll three d6 and assign each die to a roll.

For a bespoke character, distribute 11 points between the rolls, giving at least one point to each roll.

Now sort out what gear you have with your GM.

What would you use those rolls for?

Use that fighting roll in combat, to see if you hit something, or if you can avoid being hit. This also applies to physical challenges.

Use that skill roll to sneak, tamper, fiddle, search, and do anything associated with your craft.

Use that magic roll to cast magic, if that's in your power, resist magic if it comes to that, and otherwise recall fine points of lore.

Running adventures

In most cases, when characters are tested or challenged, choose an appropriate roll. If the character makes the roll, equalling or exceeding their number on a d20, they are successful.
Apply modifiers that fit the situation. Add points to the roll number to increase the difficulty, or deduct points to lower difficulty. A range from +5 to -5 should represent most conditions.

Experience

The system is intended for quick pick-up-and-play gaming, simply adapting any module or adventure or idea the GM has at hand. Hence, characters can begin with any adventure and level of expertise the GM requires.

However, if the game runs into campaign play, you can begin with an experience level of 0: adventurer. This can go up to 5: hero. The difference between a character's level and the challenge of a monster or task can be used as a modifier.

Running combat

Assume that a character's fighting roll represents the sum effect of their skill, weaponry, and armour matched against a middling foe.
Order of attacks and defence in each round of action depends on the tactical situation, so that's for the GM to decide, though generally the characters with better fighting rolls get to go first.
In each round, characters get a chance to attack and hit using their fighting roll.
The GM will decide if the foes they face have a "chance to hit" (a roll based on fighting) or simply hit automatically, as some powerful creatures will.
If a character is hit, then they can use their fighting roll as a save to try and block, parry, or dodge the impact, if their fighting style and the situation allows.

At the end of the round, deal damage to anyone who has been hit:

Light weapons: d4 (knives, staffs)
Skirmishing weapons: d6 (axes, daggers, darts)
War weapons: d8 (swords, arrows, spears)
Heavy weapons: d10 (great sword, pike)
Magical or terrible weapons: d12 (dragon claws, wraith-sword)

If a character has armour that is proof against a particular attack, then the GM can account for this by temporarily dropping the damage category (so a sword (d8) striking mail might do lighter (d6) damage).

Magic

Magic is tricky, so take your time over it. Magic effects each world differently. As a GM, you can't allow magic that would shortcut play, but magicians should be able to use their magic as effectively as other characters. 

Perhaps there's a price for gaining access to magic, such as a permanent reduction in HP or other rolls.

When you have worked out how magic works, assume that characters can effectively cast a handful of basic spells they know using a magic roll. Spells of greater power, or outside of the magician's ken, are progressively more difficult to cast.

Magic should be risky. If a roll fails disastrously, then inflict an interesting twist, side-effect, or even damage on the hapless caster.

Perilous creatures

Arihmere, as has been mentioned, is known for its haphazard and unlikely collection of perilous beasts. Here are a few, presented for use with Sword/Play.

Grimelocks

Could be mistaken for men in the distance, for they go on two legs. But their backs are broad and shaggy and their arms are longer, and they have only four digits on each hand. Their faces are like those of goats or sheep, though they have no horns. Grimelocks are silent; no one knows if they speak, or make their thoughts known only by grunts and howls. They are not needlessly cruel or given to mischief, but rather heedless and touchy, and they will slay any being they find within their territories. They weep during battles.
They have no true smith-craft, but arm themselves with spears and axes beaten out of stolen blades.

SKILLS: Tireless, Silent, Hunter
STAMINA: 10

Naggs

Naggs fly out of darkness, from caves or deep clefts in the ground. They have leathery wings, stretching as far as the arm-span of a man, but their beaks are long and blade-sharp. They attack by diving and are very swift, but cannot fly if wounded. They hunt for blood and sport, like wolves, and are most dangerous in packs where they will harass and slash before stooping to the kill.

SKILLS: Fly, Slash
STAMINA: 5

Trillits

Diminutive vermin, little taller than a man's knee. They scamper about in wastelands, preferring fens and marshes, where they hunt and scavenge. Oftentimes, they will attach the glowing seed pods of a knafer tree to a branch, creating a tiny, greenish light that they parade to lure the curious and unwary into sinkholes and other crude traps. They are cowardly, quick, dangerous only to those they trap when they mob their prey in large numbers, armed with sticks and sharpened stones. A trillit hole can often contain unregarded treasures as well as the leavings of their victims.

SKILLS: Sneak, Hide, Quick
STAMINA: 3

Taemsprits

Ancient, vile predatory spirits, that lurk in old tombs and bury-grounds. Having no bodies of their own, they dress themselves in grave-shirts, dust and bone, creating a vague mockery of the forms of the dead with cold blue eyes. Blades cannot wound them, unless spell-bound or forged of deep-steel. Their touch burns like ice. They cannot travel in daylight, and the wind and sun will destroy them.

SKILLS: Lurk, Terrify, Freeze
STAMINA: 20

Ourgarths

Ungainly, at least half again as tall as any man, with bulbous heads and features, and bones that are often uneven or ill-shaped. Ungainly and awkward in movement, they are easy to strike, but their thick hides and dense bones make them difficult to wound, and their great strength and terrible two-handed swords are to be feared. Surly and solitary by nature, they are unusually deft metal-smiths. They forge treasures and weapons of great worth, which they guard ferociously.

SKILLS: Smith, Greatsword, Massive strength
STAMINA: 18

Beyond Arihmere

Although the old realm of Arihmere is unfortunate enough to contain more than its share of dangers, there are many notable realms beyond its borders.

South: The Sundering Wars

Cordaigne, once known as the Captured Kingdom, was held entire by the Theran Empire, but the empire is now divided, and both successor states, east and south,  claim a patchwork of provinces and cities within its borders. As though the separation were not chaotic enough, the brawling Andaran Princess and the nominal King of Arihmere intervene in the simmering conflict, siding with one side and the other, warring and aligning, claiming and ceding territory, every year.

North: The Fell Lords

A hundred years ago, or more (for historians argue the dates as much as they doubt the events) it is said that Haladrin the Good was the only king ever to unite Arihmere under the one banner. Naturally, he was murdered by an ambition noble, Streigil, the Lord of Vosse and Cabel. Streigil did not rule alone, for he had nine (or eleven, or twenty three) dark lords at his side to impose his terror, and a witch-wife besides. Naturally, there was a revolt, and Streigil was struck down in battle (some say, slain). But his lords would not accept defeat, and turned to sorcery and infernal pacts, and three years later the Lord of Vosse and Cabel (or his revenant) returned to the throne with his wife as Queen and First Minister.

Whatever the truth of it, the Lady Streigil was finally undone by blade and magic, and her Fell Lords retreated far into the north. Most likely they perished among the fens and mountains, but in the north they say that the Fell Lords still rule among the black forests and dead lands where the pastures wither, planning their return, when they will recover the master and his lady from the deep, secret barrow where they were interred.

The Copper Road

The Wolve's Lane is but the end of a long road, winding from the far, forgotten south-east, from mountains, steppes, deserts and rivers and boundless forest, from sprawling kingdoms, empires, satrapies, protectorates, khanates and republics. Through all of this runs The Copper Road, named for the earliest coins that travelled between its markets, before even steel was forged.

The Arrant Sea

The Arrant Sea is wild, cold and clear. Most ships follow the shore, but there are uncounted islands and strange landings out there. For three hundred years, the Reaver Thegns have come from over the horizon, raiding or seeking kingdoms to steal, and every once in a while, the great armoured backs of the Heviathands, bristling with walls and turrets, heave into view from the shore.

On the realm of Arihmere

Arihmere is a varied country, and its terrain includes wild coastlines, valleys and moors, and rugged mountains. There are many manors and villages, watch-towers and castles, and a handful of villainous cities and deep ports.

The peoples of Arihmere, townsman and peasant alike, have long settled within stout walls and hedges. Under the manorial system, most commoners are protected by the arms of a nobleman and his knights. But the realm is divided, tugged in many directions. In the south, the impetuous King Martyn spends the campaign season mired on the Sundering Wars, draining his treasury while he clings to the ancient title of king in the city of Warrensworth. At odds with him, but scattered along the north marches, the great houses bicker over precedence and territory, in the shadow of the Withered Lands.

In truth, Arihmere, like most of the Harrowmarch, has never been under a single law, but a subject of incomplete rule, from the ramshackle empires of the Erduath and Kees, to the clannish realms of the Ellfolk, to the Reaver Thegns and the witch-realms of the Leaden Lords before their fall. Much of what is known or said of the history of Arihmere is mere guesswork, were it not for the old pits and works of these lost domains.

The only certainty is that the realm is known for its haphazard and unlikely collection of perilous beasts and strange folks, for its grimelocks and trillits, ourgarths and teamsprits, monstrous wyrms and shy fae, and countless other oddities.

The rough chances

Recently, the tinkerage has been working on a rules-lite system inspired by XD20 and Fighting Fantasy, and developing elements from And Play. The result has been a core concept (you could hardly call it even a mechanic) that could apply to any of these systems, or even to a rules ultra-light game like Sword and Backpack.

Now Sword and Backpack (S&B) is inspiring, but it's barely a system, more like the description of what would happen in play: you describe situations, propose actions, roll dice to decide. But the thought occurs that if you could table just the rough chances of success and failure, and use them consistently, you would have the basis of an RPG. Although most games use tables and extensive modifiers, what we are usually looking for are probabilities that 'feel right' and provide a satisfying balance of success and failure that's true to the circumstances.

So here's the rough chances table:

Chances	Roll	Consequences
Very Low	17+	Exceptional (Critical Hit)
Low	14+	Enhanced
Close	11+	Medium
High	7+	Light
Very High	4+	Slight
Exceptionally High	1+	Negligible (scratch)

Using the rough chances table:

• In free-form roleplaying, like And Play or S&B, you weight up the options, pick a chance, and there on the row is your roll for success (d20, of course). Add a few points to make things harder, or deduct a few to make things easier.
• In XD20, where the lower a STAT the better, the table tells you roughly what the chances are by looking at the Roll column. So if a character has a STAT of 8, chances are good. Want to make the chances better or worse? Select another row and estimate the STAT or modifier from there (so if your STAT 8 character fights a STAT 9 orc, it seems the chances are close; go for a roll of 11 or 12).
• And, if you roll for effect (higher being better) then use the Consequences column. You can even use this to judge damage.

You can also convert this table for different dice (such as 2d6 for Fighting Fantasy).

The new system, based on the rough chances table, is coming soon... -ish. Still tinkering with it.

The Soul-bell and the Silent Village - mini-scenario

You reach the village after a long day of adventuring or travel, in high spirits. But the street is dark and cold. You think at first you see a dog rummaging through a pile of kitchen scraps; then you realise that it's a wolf, the first of many.

When you break into a house, you find everyone asleep, in a slumber that cannot be broken. Anyone with witch-sight can see the larvae, the spirit-wyrms, coiled about the bodies of the sleepers. But no common sorcery can dismiss a wyrm without destroying the mind of the sleeper.

Eventually, you might find the broken crypt in the kirk-yard and the body of the poor, damned fool (an adventurer like you) who opened it. Soul-burn is a hideous death.

There are clues scattered about the tomb and notes in the priest-house that might lead you to the legend of the soul-bell. But an interfering priest of the Narrow Faith cast that relic into the ravine a hundred years or more ago, and the ravine is haunted by grimelocks, naggs, and worse.

But it might be worth finding the bell, and letting it ring from the spire before dawn. Before the spirit-worms pupate and hatch...