From 1d4chan
Rule System d20 system
Authors Robin V. Stacey
First Publication 2007
Essential Books just print this wiki page

What is it?

Written by Robin "greywulf" Stacey (not a furry), it's intended to be just the essentials of a d20 System role-playing game. The main rules fit into 1100 words, and can be printed onto a single sheet of paper. Each splatbook-like supplement also fits onto a single piece of paper. Each adventure module fits on a single sheet of paper. Any of these rulebooks rulesheets is available in "Pocketmod" format, to be printed out and then folded into an eight-page booklet.

It's supposed to be compatible with Dungeons & Dragons 3rd Edition, although it's missing some defining features of 3rd ed D&D:

  • no feats; characters and NPCs instead additional +1 to the relevant rolls
  • three stats instead of six; Charisma is omitted entirely or subsumed into the "Communication" skill
  • no Vancian magic, spells drain hitpoints from the caster instead

Microlite20 is published under the Open Gaming License, and rooted in the Dungeons & Dragons SRD, so it's free and we can mess with it quite a bit. In case we need to cover our asses in this wiki, don't forget: Core Original Microlite20 is © 2006,2007,2008 Robin V. Stacey

Core Rules, the entire thing (ya, srsly)


There are 3 stats : Strength (STR), Dexterity (DEX) and Mind (MIND).

Roll 4d6, drop lowest die. Total remaining 3 dice and allocate to one of the stats. Repeat for remaining stats.

Stat bonus = (STAT-10)/2, round down.


  • Humans get +1 to all skill rolls
  • Elves get +2 MIND
  • Dwarves get +2 STR
  • Halflings get +2 DEX


The classes are Fighter, Rogue, Mage, Cleric. Characters begin at Level 1.

Fighters wear any kind of armour and use shields. They have a +3 bonus to Physical and add +1 to all attack and damage rolls. This increases by +1 at 5th level and every five levels on

Rogues can use light armour. They have a +3 bonus to Subterfuge. If they successfully Sneak (usually sub+DEX, but depends on situation) against a foe they can add their Subterfuge skill rank to the damage of their first attack that round

Magi wear no armour. They can cast arcane spells, and gain a +3 bonus to Knowledge

Clerics can wear light or medium armour and use shields. They cast divine spells and gain +3 bonus to Communication. A Cleric can Turn Undead with a successful Magic Attack. DC is the current Hit Points of the Undead. If the DC is exceeded by 10 it is destroyed. This can be used (2 + Level + MIND Bonus) times per day.


There are just 4 skills : Physical, Subterfuge, Knowledge and Communication. Roll higher than the given Difficulty Class to succeed.

  • Skill rank = your level + any bonus due to your class or race.
  • Skill roll = d20 + skill rank + whatever stat bonus is most applicable to the use + situation modifiers

For example, Climbing would use Physical + STR bonus. Dodging a falling rock is Physical + DEX bonus. Finding a trap is Subterfuge + MIND bonus. Disabling a trap is Subterfuge + DEX bonus.

Note that there are no “saving throws” in this game; use Physical + STR or DEX bonus for Fortitude and Reflex saves. Saving against magic (Will save) is usually MIND bonus + your level.


Magi can cast any arcane spell, and Clerics any divine spell, with a spell level equal or below 1/2 their class level, rounded up. They have access to all arcane spells in the SRD spell list.

Casting a spell of any kind costs Hit Points. The cost is 1 + double the level of the spell being cast:

Spell Level 0 1 2 3 4 5 6 7 8 9
HP Cost 1 3 5 7 9 11 13 15 17 19

This loss cannot be healed normally but is recovered after 8 hours rest. There is no need to memorize spells in advance. Just because a character can cast any spell, doesn’t mean that they should. Choose spells that suit the character. Select one ‘signature’ spell per spell level from 1st upward that they prefer to use over any other. These spells are easier to cast due to familiarity, costing 1 less HP to use.

The Difficulty Class (DC) for all spells is 10 + Caster Level + Caster's MIND bonus


Hit Points = STR Stat + 1d6/Level. If HP reach 0, unconscious and near death. Further damage directly reduces STR. If that reaches 0, death.

Roll d20 + DEX bonus for initiative order. Everyone can do one thing each turn; move, attack, cast a spell, etc.

  • Melee attack bonus = STR bonus + Level
  • Missile attack bonus = DEX bonus + Level
  • Magic attack bonus = MIND bonus + Level

Add attack bonus to d20 roll. If higher than your opponent's Armour Class (AC), it’s a hit. Natural 20 is automatically a critical doing maximum damage.

Fighters and Rogues can use DEX bonus + Level as Melee attack bonus instead if wielding a light weapon. Fighters and Rogues can wield 2 light weapons and attack with both in a round if they take a -2 penalty on all attack rolls that round. Rapiers count as light weapons, but you cannot wield two rapiers at the same time.

If the total bonus is +6 or more a second attack can be made with a -5 penalty. If the total bonus is +11 or more a third attack can be made at -10, and a fourth at -15 if the total bonus is +16 or more. For example, if the total bonus is +12, three attacks can be made at +12/+7/+2. No more than four attacks can be made in a round, regardless of bonus (five if two weapons are used).

Add STR bonus to Melee damage, x2 for 2-handed weapons. Armour Class (AC) = 10 + DEX bonus + Armour bonus.


See the Monster List and the Critters monster generator. To create new monsters, assign Hit Dice (d8 for most things, d12 for Dragons and Undead). Attack bonus and skill level = number of Hit Dice. If it’s an intelligent critter, +3 bonus to one skill. Assign stats to suit. Equip and add abilities as required.

Other Hazards

Falling : 1d6 damage per 10', half damage on Phys+DEX save. DC=depth fallen in feet

Spikes : add +1 point to falling damage per 10' fallen, max +10

Poison : Phys+STR save to avoid or for half, depending on poison. Effect varies with poison type.

Extreme Heat & Cold : If not wearing suitable protection, Phys+STR save once every 10 minutes (DC 15, +1 per previous check), taking 1d6 damage on each failed save.

Level Advancement

Encounter Level = Hit Dice of defeated monsters, or the given EL for the trap, situation, etc. Add +1 for each doubling of the number of foes. e.g: 1 kobold = EL1. 2 kobolds = EL2. 4 kobolds = EL3, etc.

Add up the Encounter Levels (ELs) of every encounter you take part in. When the total = 10 x your current level, you’ve advanced to the next level. Reset the total to 0 after advancing.

Each level adds:

  • +1d6 to Hit Points
  • +1 to all attack rolls
  • +1 to all skills

If the level divides by three (i.e. level 3,6,9,etc.) add 1 point to STR, DEX or MIND.

Fighters gain +1 to their attack and damage rolls at levels 5,10,15,etc.

Clerics and Magi gain access to new spell levels at levels 3,5,7,9,etc.

The Level Advancement Example shows how this works in practice.

Monster Manual List

Name Hit Dice Armour Class Attack
Animal (small) eg Badger HD 1d8+2 (6 hp) AC 15 Claw +4 (1d2-1)
Ankheg HD 3d10+12 (28 hp) AC 18 Bite +7 (2d6+7 plus 1d4 acid)
Bugbear HD 3d8+3 (16 hp) AC 17 Morningstar +5 (1d8+2) or javelin +3 (1d6+2)
Choker HD 3d8+3 (16 hp) AC 17 Tentacle +6 (1d3+3)
Deinonychus (Raptor) HD 4d8+16 (34 hp) AC 16 Talons +6 (2d6+4)
Dire Rat HD 1d8+1 (5 hp) AC 15 Bite +4 (1d4 plus disease)
Dragon (young Red) HD 13d12+39 (123 hp) AC 21 Bite +20 (2d6+7) or breath 10d10 DC24 phys+DEX to dodge for half
Dwarf HD 1d8+2 (6 hp) AC 16 Waraxe +3 (1d10+1) or shortbow +1 (1d6)
Earth Elemental (large) HD 8d8+32 (68 hp) AC 18 Slam +12 (2d8+7)
Elf HD 1d8 (4 hp) AC 15 Longsword +2 (1d8+1) or longbow +3 (1d8)
Gargoyle HD 4d8+19 (37 hp) AC 16 Claw +6 (1d4+2)
Goblin HD 1d8+1 (5 hp) AC 15 Morningstar +2 (1d6) or javelin +3 (1d4)
Griffon HD 7d10+21 (59 hp) AC 17 Bite +11 (2d6+4)
Halfling HD 1d8+1 (5 hp) AC 16 Shortsword +3 (1d6) or light crossbow +3 (1d6)
Hellhound HD 4d8+4 (22 hp) AC 16 Bite +5 (1d8+1 plus 1d6 fire)
Hill Giant HD 12d8+48 (102 hp) AC 20 Greatclub +16 (2d8+10) or rock +8 (2d6+7)
Hobgoblin HD 1d8+2 (6 hp) AC 15 Longsword +2 (1d8+1) or javelin +2 (1d6+1)
Human Commoner HD 1d8+1 (5 hp) AC 12 Dagger +1 (1d6+1) or sling +1 (1d4)
Insect (small), e.g. Spider HD 1d8 (4 hp) AC 14 Bite +4 (1d4-2 plus poison)
Kobold HD 1d8 (4 hp) AC 15 Spear +1 (1d6-1) or sling +3 (1d3)
Ogre HD 4d8+11 (29 hp) AC 16 Greatclub +8 (2d8+7) or javelin +1 (1d8+5)
Orc HD 1d8+1 (5 hp) AC 13 Falchion +4 (2d4+4) or javelin +1 (1d6+3)
Owlbear HD 5d10+25 (52 hp) AC 15 Claw +9 (1d6+5)
Rust Monster HD 5d8+5 (27 hp) AC 18 Antennae touch +3 (rust)
Shadow HD 3d12 (19 hp) AC 13 Incorporeal touch +3 (1d6 Str)
Skeleton Warrior HD 1d12 (6 hp) AC 15 Scimitar +1 (1d6+1) or claw +1 melee (1d4+1)
Stirge HD 1d10 (5 hp) AC 16 Touch +7 (attach)
Stone Golem HD 14d10+30 (107 hp) AC 26 Slam +18 (2d10+9)
Troll HD 6d8+36 (63 hp) AC 16 Claw +9 (1d6+6)
Werewolf (hybrid form) HD 3d8+7 (20 hp) AC 16 Claw +4 (1d4+2)
Wight HD 4d12 (26 hp) AC 15 Slam +3 (1d4+1 plus energy drain)
Wolf HD 2d8+4 (13 hp) AC 14 Bite +3 (1d6+1)
Wyvern HD 7d12+14 (59 hp) AC 18 Sting +10 (1d6+4 plus poison) or Talon +10 (2d6+4) or Bite +10 (2d8+4)
Zombie HD 2d12+3 (16 hp) AC 11 Slam +2 (1d6+1) or club +2 (1d6+1)


This is some javascript that will autogenerate a mincro-sized monster for you and name them something fantasy-ish.

 function microMonster(hd){hd=hd*1;return"Name:"+neuwurd().ucfirst()+"\n"+
  "HD:"+hd+" ("+(Math.floor(hd*4.5)+randint(hd*4))+"hp), AC:"+ 
  (randint(5)+hd+10)+", Attack:"+atktypes.split(' ').randItem()+" +"+
  (hd+randint(4))+" ("+(randint(2)+1)+"d"+(2*((randint(6)+1)))+")\n";}
 var np={'W':'CT CT CX CDF CVFT CDFU CTU IT ICT A','A':'KVKVtion',
 'K':'b c d f g j l m n p qu r s t v sP','I':'ex in un re de','T':'VF VEe',
 'U':'er ish ly en ing ness ment able ive',
 'C':'b c ch d f g h j k l m n p qu r s sh t th v w y sP Rr Ll',
 'E':'b c ch d f g dg l m n p r s t th v z',
 'F':'b tch d ff g gh ck ll m n n ng p r ss sh t tt th x y zz rR sP lL',
 'P':'p t k c','Q':'b d g','L':'b f k p s','R':'P Q f th sh',
 'V':'a e i o u','D':'aw ei ow ou ie ea ai oy','X':'e i o aw ow oy'};
 var atktypes='Bite Claw Slam Gore Sting Tentacle Shock';
 atktypes=atktypes+' Weapon Weapon Weapon Weapon Weapon Weapon';
 function randint(n){return Math.floor(Math.random()*n);}
 Array.prototype.randItem=function(){return this[randint(this.length)];}
 String.prototype.ucfirst=function(){return this.substring(0,1).toUpperCase()+
 function neuwurd(){var w='W';while(w.length<40&&w.match(/[A-Z]/)){
  w=w.replace(/([A-Z])/,function(m){return np[m].split(' ').randItem();});}
  return w;}

See Also

  • Official site
  • All the pocketbooks (via Wayback machine) – this place is better than the official site for now. All the splatbooks, some of the better adventure modules. Everything in pocketmod format ready to be printed and folded.
  • System Reference Documents - Has a compilation of the core rules, a few add-ons (like Psionics, and the D20Modern version of MicroLite20) and the pocketmod versions. This page is also better than the official site for now, especially now that the author has created a new version that tries to be the MicroLite version of DungeonWorld and a dozen other *shudder* storygames.
  • Pocketmod; how to fold up the books.
  • Microlite20/Convert from d20SRD; converting the d20 System to Microlite20.