Initiative

Initiative determines the order of turns during combat.

Rolling Initiative

When combat begins, every participating combatant rolls D4 + Dexterity Modifier to determine their position in the initiative order. Participants act in order from highest to lowest Initiative. If two participants roll the same Initiative result, the one with a higher Dexterity Score goes first, though characters controlled by the same player with the same Initiative effectively act simultaneously: they can use their collective actions, movement and other turn-based resources in any order they choose.

Joining combat late

Joining combat after it has already started changes the way participants are inserted into the initiative order, and determines if the participant must wait for the current round to end before taking their turn.

Joining during the first round of combat

Joining during the first round of combat guarantees that the joining character can take their full turn. Their portrait is not greyed out.

Participants who join during the first round of combat can only be slotted into the initiative order of participants who have yet to take their turn. Any participant who has taken their turn (including passing in the case of a surprise round) is always ahead in initiative order, regardless of the initiative roll of the late joining participant.

Example: A party member attacks a group of four enemies, and rolls middle of the pack for initiative order. The first two enemies take their turn. Then, the rest of the party members join combat. They roll initiative but are, at most, slotted in near their teammate. They cannot be placed ahead of enemies that already took their turn, no matter how high the initiative roll.

Joining after the first round of combat

Joining after the first round of combat causes joining participants to automatically skip their turn. The character portraits of any characters who join are greyed out with an hourglass on it, as if they had ended their turn.

Participants who join after the first round of combat can be placed anywhere in the initiative order, including the first slot.

Initiative bonuses

Many class features, feats, magic items and consumables can improve a character’s initiative by granting additional bonuses to the roll. Many of these are also used by NPCs. Unlike in tabletop rules, it is not considered a Dexterity check, and so initiative is not affected by features or effects like Jack of All Trades or Enhance Ability: Cat's Grace (Condition).

Sources of Initiative bonuses

Source	Value	Type	Subtype	Other
Alert	+5	Feat	-	Cannot be Surprised
Elixir of Vigilance	+5	Consumable	Elixir	Cannot be Surprised
Feral Instinct	+3	Feature	-	Cannot be Surprised
Dread Ambusher	+3	Feature	-
Hellrider Longbow	+3	Weapon	Longbow
Sentinel Shield	+3	Shield	-
Rakish Audacity	+2-4	Feature	-
Assassin of Bhaal Cowl	+2	Headwear	-
Mask of Soul Perception	+2	Headwear	-
Soulbreaker Greatsword	+2	Weapon	Greatsword
Bhaalist Armour	+2	Armour	Light Armour
Elegant Studded Leather	+2	Armour	Light Armour
Elven Chain	+2	Armour	Medium Armour
Flame Enamelled Armour	+2	Armour	Medium Armour
Ambusher	+1	Weapon	Shortsword
Bow of Awareness	+1	Weapon	Shortbow
Fistbreaker Helm	+1	Headwear	-
Halberd of Vigilance	+1	Weapon	Halberd
Stalker Gloves	+1	Handwear	-
Studded Leather Armour +2	+1	Armour	Light Armour
Hide Armour +2	+1	Armour	Medium Armour
Scale Mail +2	+1	Armour	Medium Armour
Yuan-Ti Scale Mail	+1	Armour	Medium Armour

 Rakish Audacity bonus increases to +3 and +4 at rogue levels 5 and 10, respectively.

 Surprised is a special condition that can affect creatures during the first round of combat.

Overview

When one side of a combat encounter is unaware of the other side, they may be surprised. A surprised creature cannot take any Actions or Reactions for one combat round. Characters with the  Alert feat, the  Feral Instinct feature or specific items (such as the  Elixir of Vigilance) cannot be surprised.

Certain combat encounters, especially ones that occur after an in-game cutscene, are set to always surprise the party. These can usually be countered by utilizing the aforementioned features or else conditions such as  Invisible or hiding in heavily obscured areas with spells such as  Darkness before triggering them.

How to surprise enemies

The key to surprising enemies is line of sight: they must have a clear line of sight to the character surprising them. If they do not, then they begin searching for that character and are not surprised once they find them and begin combat.

This can make it challenging and counter-intuitive to successfully surprise a group of enemies. Precautions such as the following may aid in the process:

1. Use  Hide to put the entire party into stealth, including pets.
2. Ungroup the party, including pets, then select one party member as the ambusher and move them into position to trigger the surprise.
3. Keep the other party members and pets some distance away while the ambusher approaches the enemy from outside their vision cones. If they cross a vision cone in a  Clear Area then they are instantly spotted, but if they are  Lightly Obscured or  Heavily Obscured then they must succeed a  Stealth roll against the enemy's  Perception check. On a successful roll the enemies do not notice the character, but on a failed roll they initiate combat without being surprised.
4. The ambusher must initiate combat from within line of sight of the enemy. If they do, then the enemy should be surprised. However, if they are out of line of sight then the enemies begin searching for the party member and are not surprised once they find them and begin combat.
5. The way combat is started matters. Here are some key points (but the testing has not been exhaustive):
   1. Melee attacks always work.
   2. Ranged attacks done on melee range always work.
   3. Spell attack rules are either bugged or complicated. Spell attacks work nearly always for melee range and a bit less often for non-melee range. The following examples demonstrate the discrepancies:
      1.  Eldritch Blast (attack roll) works both for melee and non-melee range.
      2.  Fireball (Dexterity save) works for melee but not for non-melee range.
      3.  Fear (Wisdom save) works both for melee and non-melee range.
      4.  Magic Missile (no attack roll) works neither for melee nor for non-melee range.
      5.  Witch Bolt (attack roll) works for melee but not for non-melee range.
   4. If the attack type (melee, ranged, spell) works, it does not matter whether it hits or misses.
   5. Grenades do not work, even if you hit the enemy directly.
   6. For  Ambushing enemies, every type of attack, even grenades, work, as long as enemies have not spotted the party. This is true even if having failed the  Perception check and attack the currently empty location where the enemy will turn out to be.
6. Once the enemy is surprised, the rest of the party can be moved into position to join the fight. They are drawn into the fight once they either enter an enemy's vision cone or attack them.

If a character's Stealth is high enough then enemies sometimes fail to notice them even as their allies are being attacked and killed from a distance. This can even work with Area of Effect spells such as  Fireball as long as the party member casting it remains hidden. The enemies run around in a desperate search for the party member but cannot find them. This can be accomplished with a high Dexterity score, Proficiency and Expertise in stealth,  Advantage in dexterity or stealth checks, and certain spells and abilities such as  Pass Without Trace.

Triggering Surprised from Invisibility

The most reliable way to surprise an enemy is to become Invisible and attack them. This invisibility can come from any source (e.g.,  Potion of Invisibility,  Invisibility,  Greater Invisibility, or  Shadow of Menzoberranzan). The Quasit and Imp pets also work, as does  Wild Shape: Panther.

List of encounters with surprised participants

Act 1

• Sneaking into the Overgrown Ruins Refectory leaves  Andorn surprised.
• Approaching  Nadira surprises the Bugbear Assassin trying to ambush her.
• Interacting with certain caskets in the cave inside the Apothecary's Cellar causes an Agile Guardian to burst out and surprise the party.
• Attacking the bloated hyenas along the Risen Road leaves them surprised.
• In the Underdark, approaching the Petrified Battlefield initiates combat with a Spectator, triggering a cutscene which leaves the party members surprised.
• Approaching the Underdark Beach triggers a conversation with a Duergar. If attacked immediately, all the Duergar at the beach are left surprised. If  Gekh Coal is called and he turns hostile, the party members are surprised instead.
• In Grymforge, attacking the three Mimics always surprises the party members when interacting with them in their disguised form. Attacking them from range starts the battle without being surprised.
• Magma Mephits surprise the party members if they approach the mithral vein closest to the Adamantine Forge.

Act 2

• In the Shadow-Cursed Lands, three separate encounters with Blights can surprise the party members if they get too close to them.
• In Moonrise Towers, attacking the Mimic always surprise the party members when interacting with them in their disguised form. Attacking them from range starts the battle without being surprised.
• The meazels encountered in the Ruined Battlefield at X: -43 Y: 7 surprise the party if a DC 18 Perception check is not passed.

Act 3

• At the end of "Dribbles'" performance at the Circus of the Last Days, the party members are left surprised unless the ambush is noticed through passive Perception checks, in which case the ambushers are surprised instead.
• In Entharl's basement, for ⁠The High Harper quest, a group of doppelgangers posing as Harpers can be spoken to. A combination of dialogue checks and choices can lead to either the party members or the ambushers being surprised.