When the party of adventurers comes into contact with enemies, game-time no longer follows a sequence of turns (representing 10 minutes), but is measured in rounds (representing 1 minute), subdivided into six-second long "segments." The order of events is as follows:
- Determine Surprise (d6)
- Declare Spells and General Actions
- Determine Initiative (d6, highest result is the winner, each party acts in the segment indicated by the other party's die roll)
- Party with initiative acts first (casting spells, attacking, etc.), and results take effect (other than spells, which have casting times to complete before they take effect). Note: Some actions may allow the other side to "interrupt" with an action such as a fleeing attack or attacking charging opponents with spears set against a charge.
- Party that lost initiative acts, and results take effect (other than spells, which take effect when casting time is completed)
- The round is complete; declare spells and general actions for the next round if the battle has not been resolved.
1. Determine Surprise: If a group of combatants is surprised, its members are basically caught flat-footed and unable to act during the first few seconds of a battle.
Surprise is checked only once per combat, at the beginning of an encounter. Each side rolls a d6. If the result is a 1, the group is surprised for one segment. If the result is a 2, the group is surprised for two segments. If the result is a 3-6, the group is not surprised. In some cases, monsters or particular character classes may have special rules for surprise (e.g. some monsters cannot be surprised, others are stealthy enough that the party may be surprised on a roll of higher than 2). If a party of adventurers has alerted monsters to its presence (by hammering away at a door for a round or two, for example), the monsters will not need to make a surprise roll at all; however, merely being alert to the possibility of danger is not enough to avoid making a surprise roll. If neither of the opposing forces is surprised, play moves on to the regular combat round, described below.
If one side is surprised while another is not, the unsurprised party may act for a number of "surprise" segments. For example, if the party rolls a 1 and the monsters roll a 2, the party is surprised for one segment, the monsters are surprised for two segments, and thus the party has one surprise segment in which to act. If the party rolls a 2 and the monsters roll a 5, the party is surprised for 2 segments and the monsters (who, having rolled a 5 were not surprised at all) have both of those 2 surprise segments in which to act. Actions that would normally happen over the course of a round may be completed in one surprise segment: talking, attacking, charging, closing to melee, beginning a spell, etc., provided that it is possible for the action to take place during a single segment. In other words, a character cannot make a minute-long speech during that six seconds, nor can a spell be fully cast unless it is a one-segment spell.
A character's surprise bonus (see "Dexterity") acts to negate surprise segments if the character is surprised (or to create them, if the number is a penalty). Thus, a character with a +2 surprise bonus whose side rolled a 2 for surprise (normally a situation in which the character would be surprised for two segments) is not surprised. This can lead to a situation in which a party of adventurers is surprised with the exception of one member. For example, if the monsters rolled a 1, the party rolled a 2, and one party member had a +2 surprise bonus, the situation will resolve as follows:
- The party member is not surprised at all, because two segments of surprise are negated by his +2 bonus.
- The monsters are surprised for one segment, so the unsurprised party member may act during that first surprise segment.
- In the second surprise segment, the monsters are no longer surprised, but the rest of the party is still surprised (having rolled a 2), so both the monsters and the one unsurprised character can all take action during the second surprise segment.
Dexterity cannot create surprise, only alter the number of segments for which surprise lasts.
If a monster surprises on more than a 2 in 6 (some monster descriptions may contain text such as "surprises on 1-3"), it is possible for the monster to gain more than two segments of surprise. Against a monster that surprises on 1-3, if the party rolls a 3 and the monster is not surprised, the monster would have three surprise segments in which to act.
2. Declare Spells and General Actions: Before the two sides roll initiative, spell casters must state what spells (if any) they will be casting in that round. As the round proceeds, the spell caster may elect not to cast the spell, but may not substitute another action. This is simply because the mental preparations for casting a spell are so arduous that the caster cannot switch focus quickly enough to change actions. Non-spell casters should also tell the GM, in general terms, what they will be doing: "attacking with a sword," "using my bow," "climbing the wall," etc.
Before the players do this, the GM should already have formed a similar outline of the monsters' strategy; the GM should not base the monsters' actions on what he or she already knows the players will be doing.
3. Determine Initiative: After any surprise segments are resolved and spell casting is declared, the first combat round begins. At the beginning of a combat round, each side rolls initiative on a d6. The roll represents the six second segment of the round in which the OTHER group will be able to act; hence, the higher roll is the better roll (as the other party will act later). If the party rolls a 6 for initiative, and the monsters roll a 1, this means that the party will be acting in segment 1, and the monsters will not act until the sixth segment of the 10-segment round. Since a combat round is 10 segments long, and the initiative roll only covers the first six segments of the round, there are four remaining segments in the round after the two sides have already taken their actions: these remaining four segments are still important because spells may take effect during this time, and some combatants might "hold" (choose to delay) their actions, waiting to act until these later segments.
The dexterity bonus for surprise is not added to an individual's initiative for melee attacks, but if a character has a missile weapon in hand, he or she applies his or her missile attack bonus as a bonus to his or her initiative (as well as to the attack roll).
Initiative rolls may result in a tie. When this happens, both sides are considered to be acting simultaneously. The GM may handle this situation in any way he or she chooses—with one caveat. The damage inflicted by combatants during simultaneous initiative is inflicted even if one of the combatants dies during the round. It is possible for two combatants to kill each other during a simultaneous initiative round! Under any other circumstance, of course, the effects of damage inflicted during that segment will take effect immediately—a goblin killed in the first segment of the round will be dead (and thus unable to attack) by the time the fifth segment of the round arrives.
Some characters (and creatures) may have more than one attack routine. This does not refer to a monster that normally makes multiple attacks in a round—all of these attacks are considered to be part of one attack routine. However, a fighter whose level grants him an additional attack is considered to be making a second entire attack routine. This is perhaps most clearly seen if the reader envisions a fighter who uses a sword in one hand and a dagger in the other. These two attacks are part of an attack routine—and if the fighter is of high enough level or under the influence of a haste spell, he or she may also gain an entire additional attack routine. A creature or character with multiple attack routines cannot use the second attack routine until after the other side's initiative segment has been resolved.
Once the party with initiative has acted, the party that lost initiative may then take action.
Note about spells: Spells have a casting time, the number of segments (or rounds, turns, etc.) required to cast the spell. The spell caster does not actually begin casting the spell until his or her initiative segment. That segment is the first segment of the casting time. The spell does not "go off" until the casting has been completed.
Example: Halvaine the Arcane's party is in battle with a group of orcs. At the beginning of the round, Halvaine's player declares that the magic user will cast a spell with a 2 segment casting time. The party rolls a 5 for initiative, and the GM rolls a 4 for the orcs. Halvaine thus begins casting in the fourth segment of the round (as the ORCS rolled a 4, so Halvaine's party is acting in segment 4). The orcs attack in the fifth segment (as Halvaine's party rolled a 5), and Halvaine's spell will go off in the sixth segment (as his initiative segment is 4, and he adds the casting time of 2)—provided, of course, that the orcish attack in the fifth segment does not interrupt and thus spoil his casting.