Conditions

Conditions check something about the player. They're used in three places:

Where	What happens when a condition fails
A choice's conditions	The answer is hidden
A choice's requires	The answer is greyed out
A branch in next	That branch is skipped and the next one is tried

Each is written as an object with a type. When a list has several, all of them must pass.

"conditions": [
  { "type": "flag", "flag": "met_elder" },
  { "type": "item", "item": "minecraft:emerald", "count": 5 }
]

All conditions are checked on the server, for the player in the conversation.

flag

Passes when the player has the flag. Flags are on/off markers you set with the flag action or the /dialog flag command.

{ "type": "flag", "flag": "met_elder" }

Field	Type	Required	Default	Description
flag	string	yes	—	The flag's name, any word you like

seen

Passes when the player has finished that dialog before. Leaving early with Esc doesn't count, see when a conversation counts as finished.

{ "type": "seen", "dialog": "mypack:elder_intro" }

Field	Type	Required	Default	Description
dialog	string	yes	—	The dialog's id

relationship

Passes when the player's relationship points with that character are in a range. See Flags & Relationships.

{ "type": "relationship", "npc": "elder", "min": 5 }

Field	Type	Required	Default	Description
npc	string	yes	—	The relationship's name. Any word, it doesn't have to match a speaker
min	integer	no	—	Lowest allowed points (optional)
max	integer	no	—	Highest allowed points (optional)

"min": 5 means 5 or more. "min": 0, "max": 9 means 0 to 9. A player who has never earned points has 0.

item

Passes when the player carries at least that many of an item, anywhere in their inventory.

{ "type": "item", "item": "minecraft:apple", "count": 3 }

Field	Type	Required	Default	Description
item	string	yes	—	An item id, or a tag with # such as "#minecraft:logs" or "#c:gems"
count	integer	no	1	How many are needed

memory

Passes when the player has a memory from Nostalgic Memories, our progression mod. Always fails if that mod isn't installed.

{ "type": "memory", "memory": "mypack:fire" }

Field	Type	Required	Default	Description
memory	string	yes	—	The memory's id

command

Runs a command and passes when it succeeds with a result above 0. This is the escape hatch for anything the other conditions can't check: levels, scores, advancements, positions, other mods' commands.

{ "type": "command", "command": "execute if entity @s[level=10..]" }

Field	Type	Required	Default	Description
command	string	yes	—	The command, without /. It runs as the player, so @s is the player

More ideas:

Checks	Command
Level 10 or more	execute if entity @s[level=10..]
A scoreboard score of 3 or more	execute if score @s quests matches 3..
An advancement	execute if entity @s[advancements={minecraft:story/mine_diamond=true}]
Standing in the Nether	execute if dimension minecraft:the_nether
Night time	execute if predicate mypack:is_night (with your own predicate)

not

Passes when the condition inside fails.

{ "type": "not", "condition": { "type": "flag", "flag": "fed_wanderer" } }

any

Passes when at least one condition inside passes.

{
  "type": "any",
  "conditions": [
    { "type": "item", "item": "minecraft:bread" },
    { "type": "item", "item": "minecraft:apple" }
  ]
}

all

Passes when every condition inside passes. A normal list already works this way, so all is only needed inside any or not:

{
  "type": "not",
  "condition": {
    "type": "all",
    "conditions": [
      { "type": "flag", "flag": "quest_started" },
      { "type": "flag", "flag": "quest_done" }
    ]
  }
}