AD&D Demystified: Missile Fire Into Melee

Nothgrim (2) and Thorkell (3) are in trouble! They are currently engaged in melee with a troglodyte (4), hobgoblin (5), and two bugbears (6 & 7)! It’s up to Elestren (1)!


First the DM must assign probabilities to each melee participant according to size.

  • Small: 0.5
  • Medium: 1
  • Large (those not too much much larger than man-size): 1.5

Nothgrim (2) is dwarf, so his size is small. Thorkell (3) is a human, so his size is medium. Therefore: 0.5 + 1 = 1.5 = 1 (rounded down)

Bugbears are large; hobgoblins and troglodytes are medium. Therefore:  1.5 + 1.5 + 1 + 1 = 5

The ratio is 1 :  5. This means that if 6 arrows were fired, 1 would have a chance to hit Elestren’s (1) friends (2 & 3) and 5 would have a chance to hit the monsters (4. 5. 6. & 7). However, since Elestren (1) is only firing one arrow this round, the DM must convert the ratio to percentages.

  • Chance it will hit party: 1/6 = 17%
  • Chance it will hit monsters: 5/6 = 83%

The DM then rolls 2d10 to determine which side gets hit. The DM rolls a 15! This means that either Nothgrim (2) or Thorkell (3) has a chance to get hit. The DM then randomly determines who. Suppose even on 1d10 means Nothgrim (2) and odd means Thorkell (3).

The DM rolls a 7. Now a to hit-roll must be made against Thorkell (3).


AD&D Demystified: Initiative and Combat


Declaring Actions

One difference between AD&D and later editions is that players must declare their actions before rolling for initiative; though not explicitly listed as a step on page 61 of the DMG, it is inferred by the rules.

Initiative Determination

At the beginning of each combat round, initiative is normally determined by rolling 1d6 for each side. The side with the higher result possesses initiative for that round. Remember that each combat round consists of 10 segments. If party A rolls a 4 and party B rolls a 2, party A possesses initiative for that round and will get to act first. Which segment each party gets to act is determined by the opposite party’s initiative roll; for example, party A acts on segment 2, and party B acts on segment 4.

Dexterity Bonuses and Penalties

Individuals’ Dexterity attacking adjustment for missile weapons will modify the initiative on an individual basis. Therefore, it is possible that an individual on a side that lost initiative will still be able to perform a missile attack before the other side. These bonuses do not apply to individuals carrying more than light gear (see PHB page 102); penalties always apply.

Multiple Attack Routines

When an individual is permitted to use an attack routine multiple times during a round, special initiative rules apply.

  • If the attack routine may be used twice:
    • If possessed by one side, those individuals attack first and last
    • If possessed by both, use initiative rolls to determine who strikes first and third and second and last.
    • If an individual can only use an attack routine once per round, their attack will occur in between those with two, with order being determined by initiative rolls when necessary.
  • If three times:
    • The other party rolls for initiative to see if it or the multi-routine individuals strike first the midpoint of the round.

Note that a target must survive damage from previous attacks for one to follow their attack routine.


When opponents are begin a round over 1″ away (10′ indoors, 10 yards outdoors) from each other, melee is not possible. One side may either spend the round closing the distance or charge. Encumbered creatures are not allowed to charge.

Those receive movement bonuses:

  • Outdoors:
    • Bipeds: +33 1/3%
    • Quadruped: +50%
  • Indoors:
    • Doubled

Dexterity bonuses to armor class do not apply when charging. Those with no Dexterity AC bonus suffer a +1 to AC. There is no penalty for those with an AC of 10.

Initiative is not checked at the end of the charge. The opponent with the longer weapon attacks first. Charging creatures gain +2 to-hit if they survive.


Casting times determine when spells will be completed. If there is a tie, initiative breaks the tie.

If a spell caster is being attacked by a melee weapon and the attacker has won initiative, the weapon strike will always occur first. If initiative is tied, compare the casting time with the melee weapon’s speed factor. If the attacker loses initiative, subtract the attacker’s initiative from the weapon’s speed factor; treat negative numbers as positive, and compare the result.

If the spell caster is being attacked by a missile weapon or natural weapons without a speed factor and the attacker wins initiative, the attack will always occur first. If the attacker loses initiative or initiative is tied, the attack will occur on the segment indicated by the caster’s initiative die. Compare it to the spell’s casting time.

If the attacker has multiple attack routines, only the first attack can disrupt the spell (unless the spell’s casting time is a full round).

The caster cannot use their Dexterity bonus to avoid being hit; otherwise, the spell is disrupted. Any successful attack interrupts the spell.

Weapon Speed Factor

When initiative is tied and both are using melee weapons with speed factors, weapon speed factors determine order. The melee weapon with the lower speed factor strikes first. Under the above circumstances, one may be entitled to multiple attacks. If the difference between speed factors is 5-9, the one with the lower speed factor is entitled to 2 attacks before the opponent can attack. If the difference is 10 or greater, the one with the lower speed factor is entitled to 2 attack before the opponent can attack, and they are entitled to 1 more attack at the same time their opponent is finally able to attack.

Speed factor considerations do not apply when closing or charging to melee.

AD&D Demystified: Surprise (Even Further Clarification)


Both the Player’s Handbook and Dungeon Masters Guide make reference to a condition known as complete surprise. Unfortunately, to my knowledge, it isn’t explained. Let’s look at examples. On page 168 of the DMG under crossbow of speed:

In surprise situations it is of no help, but on complete surprise situations the held crossbow will enable its user to fire in the 2nd segment portion.

So what the heck does complete surprise mean? Could it be that regular surprise is a result of 1 on 1d6, whereas complete surprise is a result of 2?

To make things even more confusing, however, take a look at page 23 of Dungeon Module G1-2-3 Against the Giants. When describing wererats encountered in the secret room on level 2:

They always attack either by surprise (1-3) or complete surprise (4-6).

So is complete surprise is actually anything more than 3 segments? Page 51 of the PHB, in the description of the 6th level cleric spell, aerial servant:

The aerial servant will always attack by complete surprise when sent on a mission, and gain the benefit of 4 free melee rounds unless the creature is able to detect invisible objects, in which case a six-sided die is rolled, and 1 = 1 free round, 2 = 2 free rounds, 3 = 3 free rounds, 4 = 4 free rounds, and 5 or 6 = 0 free rounds (the opponent is not surprised at all).

The only reasonable conclusion, I believe, is that 4+ is complete surprise. As a side note, on page 6 of OD&D’s Eldritch Wizardry supplement:

*Complete surprise is basically a die of 2 when checking

AD&D Demystified: Surprise Segments


When a party is surprised, the individuals on the other side can perform a full round of melee attacks each surprise segment (DMG page 62).

If and individual in the surprising party has a missile weapon readied beforehand, a full round of missile attacks can be made at three times the normal rate—otherwise a full round of missile attacks at normal rate—each surprise segment.

When moving, however, only one segment of movement can be carried out (see PHB page 102).

Magic-users and clerics in a surprising party can cast a spell with a casting time of 1 segment or begin casting a spell with a longer casting time.

Spell casters seem to get shafted by these rules. Furthermore, the advantage given to readied missile weapons seems overpowered. If I’m in a party that surprises a group of monsters, and I have composite bow (rate of fire is 2) readied with an arrow, that means I get six missile attacks in the surprise segment! My potential damage range against a small or medium creature that segment goes from 2-12 to 6-36!

AD&D Demystified: Determining Encounter Distance


After determining surprise, the DM must determine the encounter distance. Determining encounter distance when outdoors is outlined on page 49 of the DMG. The base distance is 6″ to 24″ (6d4). If either party involved is surprised, the distance is modified by subtracting the value of the surprised parties’ rolls. For example, if party A is surprised and their roll was 2, the distance is 6d4 – 2. Surprise decreases the encounter distance.

Terrain will also modify the encounter distance:

Scrub— -1 per die on all 3’s and 4’s

Forest— -1 per die on all numbers

Marsh— -1 per die on all 2’s, 3’s, and 4’s

For example, suppose a roll for base distance results in: 1 + 2 + 3 + 4 + 3 = 13″. If the encounter takes places in a marsh, the rolls are modified as follows: 1 + (2 – 1) + (3 – 1) + (4 – 1) + (3 – 1) = 7″.

Determining encounter distance indoors is outlined on page 62 of the DMG. The base encounter distance indoors is 5″ to 10″ (1d6 + 4), subject to the following conditions:

  • Modify the distance, if necessary, taking into account line of sight.
  • If one of the parties is being noisy, the other has the opportunity to flee or conceal themselves. If concealment is chosen, the encounter distance is 1″ to 4″ before discovery.
  • Next, the distance must be constrained by the actual size of the room.
  • If the encounter is the result of an unplanned appearance, for example, teleporting in, the effect on distance is the same as when constrained by a room’s area.
  • If either party is surprised, the encounter distance is 1″ to 3″.
  • Lighting also affects encounter distance:
    • If reliance on a light source is necessary, then the encounter distance is limited to two times the light source’s radius.
    • The range limit of infravision and ultravision limit encounter distance as well.

AD&D Demystified: Surprise (Further Clarifications)

Parties With a Chance to Surprise

What if a party has a chance to surprise? Let’s walk through the example on page 62 of the DMG. Suppose party A is surprised on a roll of 1. Suppose party B has a 5 in 6 chance to surprise party A. 1 or 2 on 1d6 is the baseline. Since party A is surprised on only a 1, party B’s chance to surprise party A is actually 4 in 6. In other words, party A will be surprised on a result of 1-4 and lose that many segments (unless party B is surprised as well).

A More Complicated Example

What about a gray dwarf—duergar—who surprises others 3 in 6 times, but is only surprised 1 in 10 times (Unearthed Arcana page 10)? Dragon magazine (issue 133, page 74) recommends converting everything to percentages. To determine the number of lost segments, divide the d100 roll by 16 2/3.

AD&D Demystified: Surprise

Advanced Dungeons and Dragons—”first edition” or “1e”—may be the most convoluted and confusing edition of the Dungeons and Dragons roleplaying game due to Gary Gygax’s penchant for verbosity and the Dungeon Master’s Guide (DMG) poor organization. Over the course of several posts, I will attempt to clarify those rules that tend to be the most confusing—especially those regarding combat.

The steps for encounters and combat are listed on page 61 of the DMG . Step one is: “1. Determine if either or both parties are SURPRISED.” Each side—players’ party vs. monsters—rolls 1d6. Normally, a side is surprised on a result of 1 or 2. However, if a member of a side has better odds, then those odds are used for the entire side. For example, a ranger is only surprised on a result of 1 on 1d6  (PHB page 24); therefore, the ranger’s party would only be surprised on a result of 1 instead of the normal 1 or 2.

If a side is surprised, the number of pips on the die is the number of segments of inactivity that side must endure. What happens if both side are surprised? Suppose side A rolls a 1, and side B rolls a 2. Sides A and B will be inactive for one segment (surprise cancels out for that segment), and then side B will be inactive for an additional segment, while side A gets to act. However….

If a side is surprised, individuals on that side apply their reaction adjustments (Dexterity Table on page 11 if PHB). A penalty adds lost segments for that individual, and a bonus negates lost segments for that individual. HOWEVER….

Dexterity reaction bonuses only apply if the individual falls under the “normal gear” encumbrance category; however, penalties apply regardless (PHB pages 101-102).