1. Declare spells and melee movement
2. Initiative: Each side rolls 1d6.
3. Winning side acts:
   1. Monster morale (optional rule)
   2. Movement
   3. Missile attacks
   4. Spell casting
   5. Melee attacks
4. Other sides act: In initiative order.

Players must inform the referee if they intend to cast a spell or move when in melee. Other actions need not be declared.

Roll 1d6: For each side at the start of each round.
Winner: The side with the highest roll acts first. Other sides act in order, from highest to lowest roll.
Ties: Either both sides roll again or actions on both sides are resolved simultaneously. (This means that both sides might inflict deadly blows on each other!)

Combatants attacking with two-handed melee weapons (and some missile weapons—as indicated in the equipment description) always act last in the round, as an extra side with the lowest initiative.

Instead of an initiative roll per side, a roll can be made for each individual involved in a battle, modified by DEX (see Ability Scores). The referee may determine an initiative modifier for monsters that are very fast or slow, instead of applying a DEX modifier.

See Morale.

Combatants can move up to their encounter movement rate per round in feet (dungeon) or yards (wilderness).
Maximum duration: Combatants can move at this rate for at most 60 rounds.

When in melee with a foe, only the following forms of movement are possible:
Fighting withdrawal: The combatant moves backwards at up to half their encounter movement rate. There must be clear space behind the combatant.
Retreat: The combatant turns and flees from melee, moving up to their full encounter movement rate. This round: the retreating combatant cannot attack; the opponent gains a +2 bonus to all attack rolls against the retreating combatant and ignores any AC bonus due to the retreating combatant’s Shield (if applicable).

Are possible when opponents are more than 5′ from one another. See Attacking.

All missile weapons have ranges, noted in the equipment lists.
Short range: +1 bonus to attack rolls.
Medium range: No bonuses or penalties.
Long range: –1 penalty to attack rolls.
Beyond long range: Attack not possible.

Complete cover: The target cannot be hit.
Partial cover: The referee may apply an attack roll penalty from –1 to –4 (e.g. a small table might incur a –1 penalty; dense woods might incur a –4 penalty).

Freedom: The spell caster must be able to speak and move their hands. A spell caster cannot cast spells if gagged, bound, or in an area of magical silence.
Sole action: When casting a spell, no other actions can be taken in the round.
No movement: The spell caster cannot move and cast a spell in the same round.
Line of sight: Unless noted in a spell’s description, the intended target (a specific creature, object, or area) must be visible to the caster.

If a spell caster loses initiative and is successfully attacked or fails a saving throw before their turn, the spell being cast is disrupted. It fizzles out with no effect and is erased from the caster’s memory.

Are possible when opponents are 5′ or less from each other. See Attacking.

Repeat steps 3a to 3e for each side, in order of initiative (highest first).

The procedure for making an attack roll depends on whether the group is using descending or ascending AC. See below.
1s and 20s: Natural 20 attack rolls always hit. Natural 1 attack rolls always miss.
Attacks per round: PCs normally attack once per round. Some monsters have multiple attacks.
Moving and attacking: Combatants can move and attack in the same round.

PC attacks: If using the optional rule for variable damage, PC attacks deal the damage listed for the weapon used. Otherwise, PC attacks deal 1d6 damage. Melee attack damage is modified by STR.
Monster attacks: Deal the damage indicated in the monster’s description.
Minimum damage: An attack which hits always deals at least one point of damage, even when damage modifiers reduce the number rolled to 0 or less.
Death: A character or monster reduced to 0 hit points or less is killed.
Invulnerability: Some monsters are immune to certain attacks. In this case, even if an attack hits, damage is not rolled.

1. Roll 1d20.
2. Add attack bonus.
3. Apply modifiers: STR for melee; DEX, range, cover for missile attacks.
4. Result: If the result is equal to or higher than the opponent’s AC, the attack hits (referee rolls for damage).

1. Roll 1d20.
2. Apply modifiers: STR for melee; DEX, range, cover for missile attacks.
3. Determine hit AC: Look up the result in the attack matrix row for the attacker’s THAC0 (see Attack Matrix). This indicates the AC score that the attack hits.
4. Result: If the hit AC is equal to or lower than the opponent’s AC, the attack hits (referee rolls for damage).
5. Example of rolling: See Example of Using the Attack Matrix.