Game System

Test Rolls

Standard Tests

When there is need to test skill or stat, a d20 is rolled, modifiers are added to that roll, and if the result is 16 or more, the test is successful, otherwise it fails.

Skill Test
Skill test is needed, when the skill is used in stressful situation, or its normal use requires it. A normal test is made with modifiers from skill level, appropriate stat and condition. A situation modifier from +8 to -10 can be applied as required. When need to, skill test can be made by GM with secret result (most evaluating skills)

Skill Test without Skill
If the character does not have the skill, it can still be tried in most cases. Apply -8 to roll.

Stat Test
If there is need to test a stat, add 4+stat x2 (times two) to d20 roll, with 16+ being succeeds as usually.
For example, STR test with STR +2 is made as d20 roll with modifier +8.

Perception Test
When need to, character or creature perception is tested with standard test. INT-modifier times 2 is applied to roll, as is modifiers from helmet. Some things are easier to spot, some harder. If the test succeeds, the character or creature spots the thing.

Saving Throws

Save tests are needed to test, if the creature can resist some effect. The save test is simple d20 roll with modifiers, and it succeeds on a roll of 16 or more (as skill tests). The creature may add its level/3 (or up to HD/2 for some creatures) to that save, and any modifiers from attack type and resistance or vulnerability apply. A roll 20 always succeeds, and if the roll required is 1 or less, test always succeeds. Save against resisted power saves always with unmodified 14+ regardless of modifiers.

Basic save: Save without any special modifications.Note that magic falls to this category unless of some other, too
Poison save: Save versus poisons and diseases. Add CON to roll.
Stun save: Save versus stunning. No modifiers, except level. Not even from magical rings or cloaks!
Area save: Save to quickly avoid something, like opening trapdoor. Add DEX to roll.
Fear save: Add WIS and level or HD (instead of normal level/HD modifier).
Sleep save: As fear save, but no modifiers from stats (so add simply HD or level).
Illusion save: Add WIS and INT.
Mental save: Add WIS. If not covered by any save above.

If the save is against overlapping effect, add modifiers from both. For example, magical death touch is saved with bonuses from death resistance and magical resistance. If the effect has no saving throw, it can be nullified by all resisted parts, one by one.

Note that some creature have different base modifier than HD/3 to reflect their special origin.

Combat System

Combat Round

There is no strict combat round in which everyone involved in fight will act in some order. Instead, each creature acts in his or her own round, then waits for everyone else to act, and then acts again. This order is normally unchanged for the entire combat unless someone wants to delay his or her action. One combat round is something between 3 to 6 seconds.
Delayed action takes place as before the action it is response to, if it is attack action. Spells, scrolls or potions always act after action they are done in response to.

No more than 5 seconds should be used to think about own action when it is your turn! Use time between your rounds - if you cannot make up your mind, GM is free to skip your round. You may act then when you have idea what to do, and your turn is then moved to that place.

Combat Order

The order in combat is initially determined at the start of it. Creatures with initiative start the combat, and those with ready ranged attack act before melee attacks which act before spells. Otherwise, clockwise order is preferred so that there is no need to remember too exactly the order.

Combat Action

When it is creature's turn to act, it may do any of the following actions:
  • Move movement meters
  • Attack once with all attacks (may move up to half movement before melee attack). If following someone trying to run away, may strike each round if own movement speed greater, or once every second round if movement speed equal.
  • Cast a sorcery spell
  • Load a bow or crossbow (if sufficient strength)
  • Drink a ready potion, read a scroll or zap a wand
  • Take things from containers or switch weapons
Weapons can be drawn in no time, but if things previously hold in hands are not dropped but put away, action must be used for that. Dropping things in hands takes no time - the only exception is a shield, which takes one round.

Attack Rolls

Melee Attack

An attack roll in melee is:
d20 + skill-modifier + other modifiers + target AC. The AC is added normally by the GM.
If the result is 20 or more, the attack hits with at least normal damage. If the result is 20 or more before adding target AC, but less than 20 after that, damage is reduced but still hits. Otherwise, attack misses.

Unmodified roll 1 always misses, and unmodified 10 or 20 is rerolled, adding the new roll to that previous. This is continued as long as 10 or 20 is rolled.

Example: Attack with total bonuses +14 against AC 8: Roll 13 results in 35 (14+13+8) -> double damage.
Example: Attack +14 vs. AC -18. Roll 8 results in 4 (14+8-18), for a hit with 1/10 damage (because attack roll was 20 or more before AC modification).

Note: Additional damage is caused only by physical attacks; not with fire, cold, poison or other special effects.
-1self burdened
-2self overloaded
-4self taxed
-2/+2self/target blinded
-8/+2self/target scared
-4/+4*self/target grabbed
-8/+4self/target blind
+0*target surprised
+2target stunned
+6*target paralyzed
-4target invisible
*Held AC used; target gains no benefit from DEX and melee skill.

40+double damage or +30, whichever is more
30-39double damage
20-29normal damage
10-19half damage*, round down or nullify 1-3 (on d6)
-91/10 damage*, round down or nullify 1-5 (on d6)
* hits only if the attack would hit the opponent (20+) before AC modification! So these result apply only against creatures with negative AC. If the attack must penetrate armor (poison, touch effects), use nullify rules, not reduced damage.

Example: character with AC -7 is touched by the lich, final attack rolling is 16. The cold damage from touch is halved, and paralyzation effect is nullified on a d6 roll 1-3.

Ranged Attack

Ranged attack roll is done as melee attack is, but has different modifiers and is made against ranged AC (if any difference).
+skillcreature marksmanship
-4each half covered (-8 for 75% cover)
-4medium range
-8long range (over 2x range)
-16extreme range (over 4x range)
+2*target paralyzed/held
Note: Double range penalty if target is moving.
*no AC bonus from skill/DEX

Firing past other Creatures
If there is some creature in a way, apply cover modifiers. If the attack misses, it might hit the obstructing creature, roll to-hit with +2 (no other modifiers except AC of the creature).

Firing into Melee
If the creature is in melee, and is fired from side or back, missed shot may hit its combatant. Roll to-hit with +2 (no other modifiers except creature AC).

Firing into Group
Firing into a group of creatures can be rolled without normal to-hit. Just select random target and roll to-hit with +2 (no other modifiers except creature AC). Group size should be large enough, otherwise, reduce the +2. This is the only real way to hit at extreme ranges.

Skill Effects

Melee or marksmanship is directly added to attack roll.
Characters not skilled in weapon class they are using attack with -3 to-hit.
Characters with specialization in weapon type they are using are at +1 to-hit, +2 with ranged attacks.

Multiple Attacks

Characters can have multiple attacks from fast status or special weapons. In addition, if the character has high skill level, he may attack multiple times, if desired.
For each 10 melee levels, character can take an additional attack. Apply -6 to all attacks for each additional attack. So character with melee-20 may strike thrice at -12
If character has 10 or more marksmanship levels, he may load anf fire same turn, if the weapon is quickly loadable (no items needed). Apply -6 to-hit.

DEX Effects

To melee attacks, DEX/2 (round down) is added.
To ranged attacks, DEX/2 (round up) is added.
And of course DEX is added to AC unless paralyzed/held.


Inflicting Damage

If an attack hits, roll for damage, multiple or divide by appropriate modifiers from good or bad hit, resistance and vulnerability. The final result is reduced from target's HPs. In addition to pure damage, hits may have secondary effects (see special attacks) and stun.


Creature which is hit in one blow for more than 10+HD damage points is stunned until its next turn unless it saves vs. stun.


Creature dropped to 0 or less hit points is unconscious. If dropped below 0, creature is also bleeding to death. Bleeding creatures lose 1 HP each round, until dead. This bleeding can be stopped with one-round successful apply of first aid or by bringing the creature back to 0 or more hit points with healing magic.

Non-living creature dies when dropped to 0 or less hit points.


Creature dropped to negative HD/3+5+CON hit points is dead. Resurrection or similar methods are now required.


Damaged creatures can be healed with magic or healing skill. Each healing restores usually a certain percent of maximum healing points, rounded up. So marking 20% hit points means same as 20% of maximum hit points, rounded up.

In addition to active healing, passive healing happens in time: After each good 6-8 hour rest, creature is healed 20% hit points, round up. This healing can be achieved only once per day. If the creature cannot rest or is very weak from disease or hunger, no passive healing happens.

Special Attacks


The attack must hit the target. If hit with 'redeuced damage', normal nullify rules are in effect.


This attack requires eye contact. Unless the victim is prepared for it, the eye contact will happen at d6 roll 1-4 each round if fighting or otherwise watching this creature, or 1 otherwise. If avoiding the eyes, it will happen on d6 roll 1 each turn, unless almost completely covering eyes (count as blinded). This test is made at the start of each creature's turn. In addition to that, the creature with gaze attack may intentionally try to gaze at some creature, and the target must make a similar roll as it would make at the start of its own turn.


The attack attacks all targets in line, normally 10 meters. A first target specially attacked is hit as with any ranged attack (marksmanship), but with at least +20.. The bolt bounces from objects and may try to hit targets multiple times, but actual hits are not cumulative. Any other target in the path is hit with +20 modifier, no other modifiers apply. If the bolt can hit only one target, a nullified hit (because a hit to negative AC) misses the target and is checked against next one. With elemental attacks, poor to-hitsa only cause reduced damage.


The creature will grab its target if the attack is successful enough - usually requires a hit from both arms (but even reduced damage is enough). Grabbed victim may have his or her arms pinned (d6 roll: 1-2 both, 3-4 either), and can only act with free hands. His or her attacks are at -4, except against grabber. Instead of attacking, the grabbed victim may try to escape; if a d4-d4+STR roll is higher than grabber STR, victim successfully struggles free.
While trapped, victim is attacked at +4 and is counted as paralyzed for AC, but own friends require an attack roll to hit him or her with helpful spells. Grabbed victim is usually constricted each turn, causing continual damage. The grabber attacks with other attacks at +10 against own target.
If victim has 4 points higher STR, it automatically breaks free without any action.


The creature may swallow its targets with high hit-roll if they are small enough. Swallowed victims are hit each turn by digestive acids or other attacks inside creature belly, and can act only on a d6 roll 1-2 on their own turn. The effects inside are specified for each creature, but typically attacks hit automatically and cause double damage if piercing/short slashing weapons. Concussion weapons and large unwieldy weapons (like battle axes) do only normal damage. Casting fails 50% of time.

Attacks Effects

Most common attack types. Resistance, immunity and vulnerability can be against a subtype of some category.


Physical attacks include all stabbing, piercing, cutting, slashing and crushing attacks. If the attack is mainly a crushing attack, like a club from big monster or hurling into the wall, it can destroy items with its impact force. If the damage from physical attack is 20 or more, on a d6 roll of 1, some random item is broken.


The corrosive acid causes damage to all targets.
On a d6 roll of 1-3, random armor parts and items are damaged (-1 quality).


This superheated fire attack causes damage to all targets.
On a d6 roll of 1, the heat causes random potions to boil and explode, and random scrolls and other easily burnt material to catch fire and burn. Random cloth armor can be damaged (-1 to quality).


This frosty cold attack causes damage to all targets.
On a d6 roll of 1, the cold causes random potions to freeze and break, and random wands and similar objects to shatter.


This burning and shocking electricity attack causes damage to all targets. Creatures with metal torso armor are hit with +10.
Creatures are blinded on a roll d6 of 1-3 until succeed to roll 1-2 with d6 at the start of their turn. On a d6 roll of 1, the electricity causes random rings and wands to disintegrate.


This attack includes any poison or venom. The poison is not reduced by armor, instead use nullify rules - either all goes through or nothing. A normal poisonous attack causes some damage, which is modified by defense attribute, if appropriate. In addition, sometimes or even everytime, target must save vs. poison or suffer appropriate extra effect, like instant death. If a poison is magical, both defenses apply.


The target is reduced to dust, at least partially. The attack does not affect ethereal creatures, but other targets are damaged normally. On a d6 roll of 1-3, random armor or item is disintegrated.


Victim hit is contracted with disease unless disease save is made. Armor may nullify the effect completely. The exact effects of disease vary, but typical could be lowering of STR and CON by 1 and lose of 2d6 HPs from maximum each day until creature dies or disease is cured. Lost stats return normally, and HPs by d6 each day, but on roll 1 no HPs return that day, instead, one is permanently lost.

Energy Drain

This death attack drains life energy from victim. The attacker gains half the drained amount to its HP.


This death attack usually causes instant death unless basic save is made.


Most magical effects are classified as magic attacks unless the effect transform into some element before hitting the target. Note that creatures immune or resistant to magic might nullify any spell cast on them, including healing. This does not apply to spells cast on himself.


Mind attacks usually hit automatically, and force target to save vs. mind magic or be affected.


The victim is turned to stone if basic save vs. petrification fails. The creature can be later restored back to life with stone to flesh, but may be quite damaged if statue is damaged.


The victim is paralyzed if the save fails. The paralyzation is usually poison or magic inducted, and then appropriate bonus/resistance helps.
The paralyzation lasts until creature rolls 1 on a d6 at the start of its round.


The victim is put to sleep if save fails. The creature wakes up on d6 roll 1-2 every time it is hit (drop to ground and then for each hit), or each hour. The save is basic unless sleep is magic or poison inducted.


Magic Points

Each spell is powered by magic points. If the caster cannot (or do not want to!) use MPs to power his spells, the spell failure is much more propable. Magic points are normally recovered at the speed of 10% of maximum (round up) each 2 hours.

Power Level

Spells have power level which reflect the force of magic behind them. Only an experienced mage can cast safely spells with high power level. A spell has normally power level equal to spell level x3, but caster may raise that if so desired. Absolute limit for power level is caster magic level times 5!


Spell-casting can be normally done very quickly in one normal action, but some spells require more time. Such spells require continuous chanting in one place, and if interrupted somehow (like stunned), the spell fails and must be started all over again.

In any case, casting always requires hand gestures and sound.

Casting Roll

Spells do not always succeed - especially when caster is not very profient to cast them or is wearing heavy metal armor.

Most of the time all spells succeed. But if any of the following conditions met, each give some probability that spell will fail. If a spell fails, the mana-burn (see below) hits automatically, and other side effects are possible.
All penalties are cumulative.
5%For each power level over (magic level+INT)
5%For each unspent magic point required by the spell
5%Each point of metal armor (chain or plate), ignoring any quality or magical modifiers
1%Each point of non-metal armor, ignoring any quality or magical bonuses
50%Caster has a shield (or otherwise only one hand quite free)
25%Caster deaf, scared, grabbed or has gauntlets (cumulative)
10%For each month without practising
10%Hobbit or dwarf mage
Example: The mage has plate mail (5) and gauntlets. He has magic level 4 and is trying spell with power level 8, and has INT +2. He is using 4 magic points to power the spell. The final propablity for spell failure is 80% (25(plate)+25(gauntlets)+10(power level)+20(magic points)). Note that caster using 2 weapons is at 50% failure range unless drops his or her other weapon.

Mana Burn

Spell-casting is tricky operation, and may cause permanent or temporary harm on mage unless done very carefully. Each time a spell is cast, a fail roll of 10's (10,20,30...or 100) or failed spell causes possible mana-burn:
The caster is stunned unless saves vs. stun. In addition, he or she must save vs. mana burn, or suffer some damage, permanent loss of magic points or hitr points, or suffer casting inability.

Mana Burn Save
The damage or casting inability can be avoided or at least reduced with a successful mana burn save. This save is made as any other save (target number 16), but modifiers are:
+INTCaster INT
+WISCaster WIS
+lvlCaster magic level
-8Spell power level higher than caster magic level
-1Per each full 2 power levels in spell
No other bonuses apply unless especially so noted!

If the save is successful, mana-burn causes no side effects. Note that this save always fails at unmodified roll 1!

Failed Save
If the mana-burn save fails, roll d20:
1Casting inability, days
2Casting inability, minutes
3-5Casting inability, rounds
6-10Loss of d20 magic points, or all, if less.
11-14Permanent loss of 1 magic point
15Permanent loss of 1 HP
16-20Loss of d20 HP
Casting inability: The mage cannot cast spells until successfully rolls 1 at the start of his or her round, minute or day.


A creature with magic levels may enhance his saving throw against magic by using magic points. Add +1 to save for each magic point used, for a maximum of magic levels possessed by the creature. The use of magic points must be announced before the save is rolled.

Innate Magic

As spells, but require no casting roll - they are always successfully cast, as long as it is possible to cast spells. They do not cause mana burn unless noted otherwise. Hand movement and sound is still required. Magic points must be used to power it, unless noted otherwise. If not used, use standard failure probablities.

Innate Powers

As spells, but require no casting roll, no time nor gestures or sound, but usually limited to 1 per round. Do not cause mana burn unless noted otherwise. Still require magic points, unless otherwise noted. If magic points not used, may fail as with innate magic.

HDD3 RPG system (c) Kalle Marjola 1996-97. All rights reserved.