Wednesday, 13 February 2013

Old school tactical roleplaying - a simple core ruleset

It may be the best time since the mid-1980s to start playing in the expansive style of the early tactical RPGs, and a new golden age for production and play.

That said, there are still barriers to entry. The range of rulesets, supplements and ideas emerging from the OSR and beyond can be overwhelming, and references to past work and debates on fine points can be confusing and may be discouraging potential players.

This post is an attempt to offer a simple starting point. Purists may dislike it, but it may help the interested potential player grasp the whole and grow the hobby. It's not a full system, more a distillation of themes and a generalisation for the early leaps. I'm using a similar approach with a drop-in campaign at a local game store and it's helping no end.

All we really need to know to get playing is how to create characters, how to explore, how to perform actions and how to resolve encounters, so that's what this will cover.

Given the assumed setting for a lot of material is a pulpy, post-apocalyptic, low fantasy wilderness of old complexes, odd creatures and treasure, this will be covered in italics.

Note for beginners: I recommend reading it through twice, focusing on the examples, then transferring the key points into your own format. Don't worry now about longer-term elements like experience. Feel free to make changes and experiment. Most of all play.

What you need

You need a) two or more players, b) at least one six-sided die (1d6) and one 20-sided (1d20) or the equivalents, c) a means of recording information, e.g. basic stationery or similar software and both d) plenty of imagination and e) a willingness to actually use it.

The players together decide the general nature of the game world. One player is the GM, who describes the immediate situation in this world. The others each guide one or more characters through it, in theory working together as a party. The GM guides any other characters they meet on the way and updates the game world as they all interact with it.

There are many ways to create a world and a lot of materials cover this. A simple map with notes on the immediate situation in each location should be enough to start off with.

Notation: A roll of '1d3' is a roll of 1d6 with the result halved (rounding up), a '1d2' is 1d6 divided by three (rounding up), and '2d6' is two rolls of 1d6 with the results then totalled.


1.1.  Level of ability

A character starts at the first level of ability (L1) and gains new levels with experience.

Acceptable sources of experience and amounts required for each level are agreed by all of the players, the GM calculating and awarding this at a suitable time. Sources could include treasure recovered, enemies defeated, distance travelled and discoveries made.

Experience is gained by the party as a whole, each member receiving one equal share.

For a world like the assumed setting, the sources of experience could be treasure recovered and enemies defeated. As a simple initial guide, a character could gain one level each time the character a) recovered a small fortune or b) outwitted, incapacitated or killed the equivalent of a small army, or c) some other equal combination of the two, e.g. half a small fortune and half a small army. For reference, Bilbo might have gained a level over the whole of his first adventure, from Bag End to the Lonely Mountain and back again.

1.2.  Character profile

A character is represented by up to five main numbers. The first three are modifiers which relate to the character's basic nature, for body (B), mind (M) and spirit (S). To determine whether a character has any of these modifiers, roll 1d6 for each attribute in order, first B, then M, then S. On a roll of 1-2, the modifier is -1. On a roll of 5-6, it is +1.

e.g. Rolling a 2, 3 and 5 for B, M, and S gives a character B -1 and S +1.

The next number is points of hardiness (H), i.e. a measure of the hits etc. a character can take. This falls and rises as a character is harmed and heals, but may not exceed the maximum, i.e. 1d6 H per level of ability. The maximum H for L1 is rolled during creation and it rises by 1d6 each time the character gains a level. If the character has a modifier for S, this is added to each such roll, but the result of the roll is never below 1.

e.g. Rolling a 3 for H would usually give a starting character 3 H, but with S +1 our character has 4 H (3 + 1). If this character reached L2, a further 1d6 would be rolled; if it was a 5, maximum H would become 10 (4 + 5 + 1).

The final number is resistance to rarer sources of harm, such as venom, radiation and magic. Each time a character would be affected, harmed or killed by any such source, the guiding player may immediately roll 1d20 in an attempt to save the character. Resistance at L1 is 15+, i.e. on a roll of 15-20, the character is saved. This improves by one point each time the character gains a level, to 14+ at L2, 13+ at L3, and so on.

The GM may allow characters to have specific skills, and sets a range for initial wealth.

For a world like the assumed setting, a character could be allowed 1d3 of the following: a) great vigour, i.e. +1 H per ability level; b) arcane knowledge, i.e. the ability to cast spells; c) divine audience, i.e. the ability to invoke the intervention of a deity; d) deft touch, i.e. +1 to rolls for actions which involve moving with care, in silence or unseen, and detecting, disarming or working with mechanisms; e) heightened awareness, i.e. the ability to see in the dark, sensitivity to subtle changes in the environment and +1 to rolls to find anything hidden; f) high tolerance, i.e. two extra points of resistance; g) monstrous form, i.e. one extra roll per strike, i.e. a powerful bite, claws or another physical feature. Options a), d), f) and g) may be chosen twice.

This makes it possible to create many of the staples of this kind of fantasy, such as barbarians (a x 2), mages (b + f), warrior priests (a + c) and footpads (d), plus dwarves (a + e + f) and elves (b + e), and even monsters.

A character starts with 3d6 x 5 gold pieces (GP) and may spend any on initial equipment. Melee weapons cost their maximum damage result in GP. Ranged weapons cost their maximum damage result x 10 GP, and a set of 6+1d6 projectiles costs 1 GP. Armour costs its modifier squared multiplied by five (e.g. chainmail (+3) costs 45 GP (3
2 x 5)). Other items cost 1 GP for 6+1d6 if basic, 1d6 GP if simple or common, 1d6 x 10 GP if complex or rare. An item weighs its GP value in lbs unless the GM judges otherwise; 5 GP in coins is 1 lb. A sack holds 25 lb, a pack 50 lbs. Market behaviour and ranges for treasure value are determined by the GM.

Here is one way our starting character could turn out with
options d) and f) and more or less average costs.

    Sample starting character

Glam  (goblinoid ratcatcher, L1)     B -1     S +1     4 H     14+     deft touch
Dagger (1d3), leather jerkin (+1), vial of poison, 3 torches, flask (3 pts. oil), tinderbox, 25' rope, waterskin (1 pt. water), rations (4 days), bedroll, pack 
Load: c. 25 lbs

1.3.  Resource management

Tracking weight, light, water and food may seem unattractive, but can lead to rewarding developments in play: loading packs with too much equipment or loot can make escape harder, light sources can fail at inopportune moments and thirst and hunger can strike, all of which prompt innovation by players and can lead to a cascade of unexpected consequences. In this respect keeping track of time is fundamental.


2.1.  Time

The GM keeps track of time in the game world. For convenience this is measured in increments of five minutes, i.e. 12 such increments is one hour in the game world. In each five-minute increment every character gets their turn to move and attempt actions.

In each five-minute increment a humanoid character may move up to 1,000' (c. 350 m, i.e. c. 3 miles / 5 km per hour) in the open wilderness or up to 100' (c. 35 m, i.e. 1/4 mile / hr.) in a busy, enclosed and/or dark place like a forest, a market or an underground complex.

For every full 50 lbs (c. 25 kg) a character carries, that character's speed drops by 20%.

e.g. Glam carries his pack (c. 25 lbs) to a delve at no penalty, but coming back with three extra sacks - holding 40 lbs of treasure each (a total of c. 145 lbs, i.e. two full 50 lbs) - he moves at 600' every five minutes if in the open wilderness (2 x 200' = 400'; 1,000' - 400' = 600') and 60' in a tighter space.

As well as moving, each character may attempt any actions as and when appropriate.

2.2.  Light sources

If the party may need to explore in the dark, the GM will need to set strengths and burn times for available light sources. Actions performed in darkness incur a modifier of -5.

For a world like the assumed setting, a candle could have a 10' radius and burn for 5 hrs., a torch doused in 1 pt. of oil a 25' radius for 1 hr., and a lantern filled with 1 pt. of oil a 25' radius and 360° arc (wide beam) or 50' and 45° (narrow), for 5 hrs. Electric lamps or similar may have double or triple the strength of a lantern.

2.3.  Unexpected encounters

For every five minutes in-world the GM rolls 1d20. On a 20, an encounter occurs (see 4.). The GM may modify the roll if the area is busy or the party draws attention to itself.


If a character wishes to attempt an action and the GM judges that success is certain, the action is performed automatically. If success is uncertain, a check is made: the guiding player rolls 1d20 and the modifier for the most relevant attribute is added to the roll. On a result of 10+, the attempt succeeds and the action occurs. 

A roll of 1 always fails, while a roll of 20 always succeeds, in both cases spectacularly so. The GM may introduce benefits and/or penalties appropriate to a situation, interpret the margin of success or failure and judge the effect achieved in any spectacular cases.

Whenever the GM is uncertain that a thing will occur, 1d6 is rolled. On a 5+, it does.

e.g. Glam wishes to leap a partially flooded junction inhabited by mutant leeches. The GM asks for a check using B. A 10 is rolled on 1d20, but Glam has B -1 so this is modified to 9. Glam falls short. However, since the margin of failure was very small the GM assumes that he lands in the shallows and rules that if the leeches prove hostile, they will have only a single round in which to strike. If he had rolled lower, he could have struck hidden debris (present on a 5+; 1d3 damage) or perhaps slipped on the slimy bottom (a further check to avoid falling prone (see 4.3.2.)). Of course, if Glam had been less headstrong, the risk of rolling could have been removed, perhaps by gathering stones and testing the leeches' behaviour, and if distracted wading across, or by using furniture or debris to form a makeshift but stable bridge, perhaps even by pouring the poison into the water to weaken or kill the leeches (the GM judging potency and volume). The bridge would also allow him to peer into the water for items of value (one or more bodies or a concealed hoard present on a 5+), but the noise of the construction may increase the chance of an encounter...


4.1.  Initial relationships

If a party encounters a potential threat, the entity will be met at a distance of 1d20 x 50' in open wilderness and a distance of 1d20 x 5' in a busy, enclosed and/or dark place.

If the GM does not know the general intent of this entity, 1d6 is rolled for its response, adding the S modifier of the member of the party closest to it. On a result of up to 2, the potential threat is initially hostile towards the party. On a result of 5+, initially friendly.

4.2.  Simplified profiles

For economy or ease of reference in combat, profiles can follow an abbreviated format.

Glam   (L1)   B -1   Dagger (1d3)  Leather jerkin (+1)   4 H   14+   deft touch

4.3.  Combat

If an entity is hostile, measurement of time moves to shorter increments of five seconds better suited to a round of combat, i.e. 60 increments is five minutes in the game world.

At the start of each round, 1d20 is rolled for each character and modified by that character's M. Characters act in descending order of this result, the character with the highest result first. If two or more have the same result, they act simultaneously. The GM may apply additional modifiers to the first roll of a combat if one side is surprised.

Each round a character may move up to 20% of normal speed (see above; usually 200' in the open wilderness and 20' in a busy, enclosed and/or dark place) and attempt one action, whether a strike, a shot, a spell or an invocation, or another action entirely.

4.3.1.  Striking

A character is able to strike a target within 5'. As with every action for which success is uncertain, roll 1d20, a 10+ succeeds (see 3.). Here the roll is modified by a) the attacker's B, b) the defender's M and c) the defender's armour modifier, if any.

Note that the defender's usual M and armour modifiers switch sign for the purpose of this roll, so if the modifier is usually positive it lowers the roll, if usually negative it raises it.

In addition, the attacker gains a further +1 to the roll for every three full levels of ability. 

e.g. Glam (L1, B -1) darts forward and attempts to strike a wily brigand chief (L2, M +1, H 7) who is wearing chainmail (+3). A 16 is rolled, but with Glam's modifier for B this becomes 15. The brigand's M +1 lowers the result further, to 14, and his armour lowers it to 11. However this is still enough to succeed. (Essentially Glam needed a 15+ (10 + 1 + 1 + 3 = 15).)

Success means that the attacker does harm to the defender, i.e. the defender's H is reduced. The amount of H lost depends on how the attacker is armed; the amount is also modified by the attacker's B, to represent the amount of power behind a strike.

For a world like the assumed setting: the limbs of a humanoid could do 1 H of harm; short, simple and/or improvised weapons (like claws, daggers, clubs, table legs and slings) could do 1d3 H; longer, more complex and/or standard weapons (like tusks, axes, swords and bows) could do 1d6 H; and much longer, more complex and/or two-handed weapons (like spears, battleaxes and crossbows) could do 1d6+1 H. Highly advanced weaponry could do double this, while advanced armours may boost B, H and/or resistance.

e.g. Glam has a dagger so 1d3 is rolled for harm done to the brigand. A 3 is rolled, but with B -1 this becomes 2; the brigand's H falls from 7 to 5.
If Glam had used cunning to maneouvre for a stab in the back, the GM might have allowed a modifier of +5 to the first roll and doubled the harm.

If a character has more than one roll per strike, all of the rolls are made simultaneously as a set of linked actions, and are modified in the same way. Each success does harm.

4.3.2.  Shooting

A shot is also treated as any other action for which success is uncertain, i.e roll 1d20, a 10+ succeeds (see 3.). Here the roll is modified by a) the attacker's M, but also affected by b) the distance to the target. Every weapon has an accuracy in feet, and for each full multiple of this distance to the target, the roll to hit is modified by -1.

For a world like the assumed setting: objects could be thrown with an accuracy of 10' modified by B; simple and/or low-powered weapons like slings, shortbows and light crossbows could have an accuracy of 25', and more complex and/or high-powered weapons like longbows and heavy crossbows could have an accuracy of 50'. Firearms could have double or triple the accuracy. Loading in the case of crossbows and firearms with no automatic feed requires one action; this is always uncertain if black powder or the equivalent is loose.

e.g. Glam hurls a rock at a bubbling alembic from 50' away. With B -1 the accuracy for the rock is 9', meaning the modifier is -5 (50' / 9' = 5 5/9). A 6 is rolled, making the result 1 (but not a natural 1). The result is so poor that the GM judges there is a chance of the rock hitting a character standing close to the line of fire, who must now take a check modified by B to avoid it. It if had been a natural 1, the GM may have judged that Glam sprained his arm (for a -1 modifier to strikes) or simply overbalanced and fell prone (one certain action to stand; a -5 modifier in the meantime).

4.4.  Injury and death

If a character's H falls to 0, the character is incapacitated until it rises again. Each point by which H falls below 0 reduces maximum H by 1. If this reaches 0, the character dies.

Losing at least half the maximum at once breaks a limb / damages an organ; losing the maximum severs / destroys one. H is recovered naturally at a rate of 1d2 per day of rest.


4.5.1.  Arcane knowledge / divine audience (inspired by the Dying Earth series and Lone Wolf novelisations)

Ability to cast spells / invoke divine intervention involves: a) capacity, b) acquisition and c) preparation.

A starting character (L1) with arcane knowledge / divine audience a) has the capacity to learn one spell / invocation and b) actually has acquired and learnt one (the guiding player chooses from those made available by the GM at character creation), and c) must spend five seconds preparing this when well-rested and unrestrained (in the event of restraint and/or lack of rest, major penalties should be applied by the GM). 

Once prepared, it may be cast / invoked within 1d3 x 10 mins. (the GM rolls secretly). This process is treated as any other action which is uncertain. Each attempt to cast / invoke reduces the caster's / invoker's H by 1 per point of spell level. Random ranges, durations and effects are rolled only after the spell / invocation has been performed successfully ; the GM may further modify these based on the degree of success or failure.

In addition, all ranges, durations and numerically expressed effects rise by one multiple with each further level of caster ability. If a given number has a variable and a fixed element, multiply the fixed element only.

e.g. The L1 spell Smite Foe has a range of 2d6 x 10' and does 1d6 H of harm when cast by an L1 mage, but 2d6 x 20' and 2d6 H when the spell is cast by an L2 mage, and 2d6 x 40' and 3d6 H when cast by an L3. The L2 spell Vanish affects one entity when cast by an L2 mage, but two entities when cast by an L3 mage, and three when cast by an L4, assuming in each case that the mage can actually touch this number of entities at once. However, Smite Foe always costs 1 H to cast regardless of caster level and Vanish always 2 H.

The character gains the capacity to cast one new spell / invoke one new intervention for each level of ability attained, but this may be of no higher than the character's current level. To learn a spell / invocation to fill any excess capacity the character must either find one which has been recorded and be able to read it or seek a master. All of the spells / invocations which are learnt can be prepared in the same five minutes.

e.g. A starting mage has can learn and has learnt one L1 spell, and can prepare it in five seconds. If the mage becomes L2, capacity for a second L1 spell or first L2 is gained, but it must still be acquired and learnt. Whether or not a new spell is learnt, if the mage becomes L3, capacity for a third is gained, either L1, L2 or L3, whichever is learnt first.

In the case of divine audience, the patron deity is agreed by the player and GM at character creation. Certain invocations may be attempted in either form, but the patron may be angered by an inappropriate use.

4.5.2.  Sample spells and invocations

  • Smite Foe (L1, Line of Sight, Range 2d6x10', Instant) The caster selects one entity visible to the caster and within 2d6x10'. The entity is struck instantly by a blast of energy and loses 1d6 H.
  • Decipher Arcana (L1, Line of Sight, 2d6 mins.) The caster may read arcane knowledge recorded by another character, and need not recast to read this again in future. If the knowledge is a written spell and the caster has access to it for 1d6 days per spell level, the caster learns it.
  • Vanish (L2, Contact, -) The caster causes one entity to become invisible by touching this entity as the spell is cast. The caster may cancel the effect at any time by touching the entity again.
  • Do / Undo Harm (L1, Contact, Instant) The invoker causes one entity either to lose or to regain up to 1d6 H instantly, and does so by touching this entity as the intervention is invoked.
  • Purify / Contaminate (L1, 1d3x10', Instant) The invoker transforms up to one cubic foot of matter visible to the invoker and within 1d3x10'. If unfit for consumption, it nourishes; if fit, it spoils.
  • Reveal Intent (L2, 2d6 x 10', 2d6x10 mins.) The invoker senses the degree of hostility felt by all entities within 2d6x10'; if the GM does not know, a response is rolled as if for an encounter.

Appendix: What Next?

For some context and relevant theory, as well as plenty of inspiration and links to more of the varied material relatively easy to adapt to this ruleset, you could try a few of these.

 aesthetic  -  brevity  -  candy  -  carousing  -  combat  -  dice  -  dozens  -  evolution 
 freedom  -  histories  -  industry  -  inheritance  -  interiors  -  joesky  -  lance  -  loot 
 loss   -   mongrel   -   musings (pdf)  -   prep   -   resources   -   retroclones   -   rules 
 simplicity  -  space  -  spells  -  stitchery  -  titanswheelbarrowwizardsworlds 

Version 1.02


Cygnus said...

Welcome back, Porky!

For something intended as a brief vanilla introduction for new players, this thing has some cool flavor. "Bubbling alembic!" :-) Have you considered doing up a PDF, maybe with some art, that could be printed and folded into a handy little booklet?

(I'd happily offer my LaTeX services to give that a go myself, but right now I'm gearing up for April's A-Z marathon and also trying to finish a Roman-themed OSR adventure, despite the contest that inspired it being over...)

Tim Shorts said...

You've been saving up. Good to see you back Porky. I think one of the obstacles when entering gaming these days is back when I started there were only two games I knew of D&D and T&T. So when you gamed everyone used the same ruleset. These days there are dozens of rulesets so pinning just one down could be a problem for a starter. Good post.

John Till said...

Glad to see you back, Porky!

Porky said...

@ Cygnus - For all the trappings we see, alembics don't too often get a mention. Have you seen the spells in the link at the end? You might find some of them very interesting. Hereticwerks are working on a whole other level.

I thought about a pdf too, but I'll wait a bit first, to give the errors and oversights time to emerge. It's already on version 1.01 since posting and there may be much more to fix still - the notes I use are very brief and scaling them up to a coherent text means filling in a few blanks, things kept mostly in memory like variables based on level of ability. I've added the version number right at the end so everyone can keep track.

I admire you for even thinking about the A-Z again, let alone working on it this far out. It makes sense though, given the pace, and I think your theme deserves the time. It's an excellent choice and it could do a lot of good.

@ Tim Shorts - Thanks Tim. That's more or less it. Stripping out the assumed setting suggestions and examples, it's really a simple framework, almost a single key mechanism with a series of simple steps. The obvious metaphor is training wheels, a way to get a feel for how the bike works, but I think it's much more like the first big bike just because of what it can do. If the time comes to move on, there are lots more bikes on the market that might offer another kind of ride, or with bits that can be used to soup this model up. Hopefully it's the fun that shines through. It's really about the thrill and the wonder of moving.

@ John Till - Glad to hear it and to see you too. Very friendly faces.