diff --git a/api/functions/Card/AddCannotBeFlipSummoned.yml b/api/functions/Card/AddCannotBeFlipSummoned.yml
new file mode 100644
index 00000000..c915099e
--- /dev/null
+++ b/api/functions/Card/AddCannotBeFlipSummoned.yml
@@ -0,0 +1,17 @@
+---!function
+name: AddCannotBeFlipSummoned
+namespace: Card
+description: >-
+  Creates and registers an [Effect](/api/types/Effect) to a monster card
+  that applies a "Cannot be Flip Summoned" Summoning condition to it
+summary: Adds a "Cannot be Flip Summoned" Summoning condition to a monster
+parameters:
+  - name: c
+    type: [ Card ]
+    description: The monster to register the effect to.
+returns:
+  - type: [ Effect ]
+    description: The registered effect.
+status:
+  index: stable
+tags: [ registers-effect ]
diff --git a/api/functions/Card/AddCannotBeNormalSummoned.yml b/api/functions/Card/AddCannotBeNormalSummoned.yml
new file mode 100644
index 00000000..8bdedc88
--- /dev/null
+++ b/api/functions/Card/AddCannotBeNormalSummoned.yml
@@ -0,0 +1,17 @@
+---!function
+name: AddCannotBeNormalSummoned
+namespace: Card
+description: >-
+  Creates and registers an [Effect](/api/types/Effect) to a monster card
+  that applies a "Cannot be Normal Summoned" Summoning condition to it
+summary: Adds a "Cannot be Normal Summoned" Summoning condition to a monster
+parameters:
+  - name: c
+    type: [ Card ]
+    description: The monster to register the effect to.
+returns:
+  - type: [ Effect ]
+    description: The registered effect.
+status:
+  index: stable
+tags: [ registers-effect ]
diff --git a/api/functions/Card/IsAttributeExcept.yml b/api/functions/Card/IsAttributeExcept.yml
index a22c9ea5..cde92760 100644
--- a/api/functions/Card/IsAttributeExcept.yml
+++ b/api/functions/Card/IsAttributeExcept.yml
@@ -1,30 +1,50 @@
 ---!function
 name: IsAttributeExcept
 namespace: Card
-description: >-
-  Checks if (Card c) has any attribute other than (int att). If the optional parameters are passed, does the checks by calling the equivalent behavior with such parameters with Card.GetAttribute
+description: Checks if a card currently has any attribute other than a specified attribute(s).
+summary: Checks if a card currently has any attribute other than a specified attribute(s)
 status:
   index: stable
+aliases:
+  - name: Card.IsDifferentAttribute
+    status:
+      index: deleted
 parameters:
-  - name: c
+  - &c
+    name: c
     type: [ Card ]
-    description: (To be added)
-  - name: att
+    description: The monster to check the attribute(s) of.
+  - &attr
+    name: attr
     type: [ int ]
-    description: (To be added)
-  - name: scard
-    type: [ Card ]
-    description: (To be added)
-    required: false
-  - name: sumtype
-    type: [ int ]
-    description: (To be added)
-    required: false
-  - name: playerid
-    type: [ int ]
-    description: (To be added)
-    required: false
+    description: >-
+      Composite [MonsterAttribute](/api/enums/MonsterAttribute) value to check.
+      `c` needs to have any attribute other than this value.
 returns:
   - type: [ bool ]
-    description: (To be added)
-tags: [ under-construction ]
+    description: >-
+      `true` if `c` has any attribute other than `attr`, `false` otherwise.
+overloads:
+  - description: Checks if a card would be treated as any attribute other than a specified attribute(s) if it would be used as material to Summon a monster.
+    parameters:
+      - *c
+      - *attr
+      - name: scard
+        type: [ Card ]
+        description: The monster that would be Summoned using `c` as material.
+      - name: sumtype
+        type: [ int ]
+        description: The [type of Summon](/api/enums/SummonType).
+      - name: playerid
+        type: [ int ]
+        description: The player that would perform the Summon.
+    returns:
+      - type: [ bool ]
+        description: >-
+          `true` if `c` would be treated as any attribute other than `attr` when used as material for the Summon of `scard`, `false` otherwise.
+suggestedLinks:
+  - name: Card.IsAttribute
+    link: /api/functions/Card/IsAttribute
+  - name: Card.GetAttribute
+    link: /api/functions/Card/GetAttribute
+tags: [ card-check, attribute-related ]
diff --git a/api/functions/Card/IsDifferentAttribute.yml b/api/functions/Card/IsDifferentAttribute.yml
deleted file mode 100644
index 26d366bb..00000000
--- a/api/functions/Card/IsDifferentAttribute.yml
+++ /dev/null
@@ -1,18 +0,0 @@
----!function
-name: IsDifferentAttribute
-namespace: Card
-description: >-
-  Deprecated function. Use Card.IsAttributeExcept
-status:
-  index: stable
-parameters:
-  - name: c
-    type: [ Card ]
-    description: (To be added)
-  - name: att
-    type: [ int ]
-    description: (To be added)
-returns:
-  - type: [ bool ]
-    description: (To be added)
-tags: [ under-construction ]
diff --git a/api/functions/Card/IsDifferentRace.yml b/api/functions/Card/IsDifferentRace.yml
deleted file mode 100644
index 0da857e6..00000000
--- a/api/functions/Card/IsDifferentRace.yml
+++ /dev/null
@@ -1,18 +0,0 @@
----!function
-name: IsDifferentRace
-namespace: Card
-description: >-
-  Returns if (Card c) does not have Race (int race)
-status:
-  index: stable
-parameters:
-  - name: c
-    type: [ Card ]
-    description: (To be added)
-  - name: race
-    type: [ int ]
-    description: (To be added)
-returns:
-  - type: [ bool ]
-    description: (To be added)
-tags: [ under-construction ]
diff --git a/api/functions/Card/IsEffectMonster.yml b/api/functions/Card/IsEffectMonster.yml
new file mode 100644
index 00000000..a622b948
--- /dev/null
+++ b/api/functions/Card/IsEffectMonster.yml
@@ -0,0 +1,17 @@
+---!function
+name: IsEffectMonster
+namespace: Card
+description: >-
+  Checks if a card is currently an [Effect Monster](https://yugipedia.com/wiki/Effect_Monster).
+summary: Checks if a card is currently an Effect Monster.
+parameters:
+  - name: c
+    type: [ Card ]
+    description: The card to check.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if the card is currently an Effect Monster, `false` otherwise.
+status:
+  index: stable
+tags: [ card-check, card-type-related ]
diff --git a/api/functions/Card/IsFusionMonster.yml b/api/functions/Card/IsFusionMonster.yml
new file mode 100644
index 00000000..d0bb91a2
--- /dev/null
+++ b/api/functions/Card/IsFusionMonster.yml
@@ -0,0 +1,17 @@
+---!function
+name: IsFusionMonster
+namespace: Card
+description: >-
+  Checks if a card is currently a [Fusion Monster](https://yugipedia.com/wiki/Fusion_Monster).
+summary: Checks if a card is currently a Fusion Monster.
+parameters:
+  - name: c
+    type: [ Card ]
+    description: The card to check.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if the card is currently a Fusion Monster, `false` otherwise.
+status:
+  index: stable
+tags: [ card-check, card-type-related ]
diff --git a/api/functions/Card/IsPendulumMonster.yml b/api/functions/Card/IsPendulumMonster.yml
new file mode 100644
index 00000000..ae73adb9
--- /dev/null
+++ b/api/functions/Card/IsPendulumMonster.yml
@@ -0,0 +1,17 @@
+---!function
+name: IsPendulumMonster
+namespace: Card
+description: >-
+  Checks if a card is currently a [Pendulum Monster](https://yugipedia.com/wiki/Pendulum_Monster).
+summary: Checks if a card is currently a Pendulum Monster.
+parameters:
+  - name: c
+    type: [ Card ]
+    description: The card to check.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if the card is currently a Pendulum Monster, `false` otherwise.
+status:
+  index: stable
+tags: [ card-check, card-type-related ]
diff --git a/api/functions/Card/IsRaceExcept.yml b/api/functions/Card/IsRaceExcept.yml
new file mode 100644
index 00000000..f4a6cb12
--- /dev/null
+++ b/api/functions/Card/IsRaceExcept.yml
@@ -0,0 +1,50 @@
+---!function
+name: IsRaceExcept
+namespace: Card
+description: &desc Checks if a card currently has any race other than a specified race(s).
+summary: *desc
+status:
+  index: stable
+aliases:
+  - name: Card.IsDifferentRace
+    status:
+      index: deleted
+parameters:
+  - &c
+    name: c
+    type: [ Card ]
+    description: The monster to check the race(s) of.
+  - &race
+    name: race
+    type: [ int ]
+    description: >-
+      Composite [MonsterRace](/api/enums/MonsterRace) value to check.
+      `c` needs to have any race other than this value.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if `c` has any race other than the specified `race`, `false` otherwise.
+overloads:
+  - description: Checks if a card would be treated as any race other than a specified race(s) if it would be used as material to Summon a monster.
+    parameters:
+      - *c
+      - *race
+      - name: scard
+        type: [ Card ]
+        description: The monster that would be Summoned using `c` as material.
+      - name: sumtype
+        type: [ int ]
+        description: The [type of Summon](/api/enums/SummonType).
+      - name: playerid
+        type: [ int ]
+        description: The player that would perform the Summon.
+    returns:
+      - type: [ bool ]
+        description: >-
+          `true` if `c` would be treated as any race other than the specified `race` when used as material for the Summon of `scard`, `false` otherwise.
+suggestedLinks:
+  - name: Card.IsRace
+    link: /api/functions/Card/IsRace
+  - name: Card.GetRace
+    link: /api/functions/Card/GetRace
+tags: [ card-check, race-related ]
diff --git a/api/functions/Card/IsSynchroMonster.yml b/api/functions/Card/IsSynchroMonster.yml
new file mode 100644
index 00000000..fedee7ee
--- /dev/null
+++ b/api/functions/Card/IsSynchroMonster.yml
@@ -0,0 +1,17 @@
+---!function
+name: IsSynchroMonster
+namespace: Card
+description: >-
+  Checks if a card is currently a [Synchro Monster](https://yugipedia.com/wiki/Synchro_Monster).
+summary: Checks if a card is currently a Synchro Monster.
+parameters:
+  - name: c
+    type: [ Card ]
+    description: The card to check.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if the card is currently a Synchro Monster, `false` otherwise.
+status:
+  index: stable
+tags: [ card-check, card-type-related ]
diff --git a/api/functions/Card/IsXyzMonster.yml b/api/functions/Card/IsXyzMonster.yml
new file mode 100644
index 00000000..dec26e5a
--- /dev/null
+++ b/api/functions/Card/IsXyzMonster.yml
@@ -0,0 +1,17 @@
+---!function
+name: IsXyzMonster
+namespace: Card
+description: >-
+  Checks if a card is currently an [Xyz Monster](https://yugipedia.com/wiki/Xyz_Monster).
+summary: Checks if a card is currently an Xyz Monster.
+parameters:
+  - name: c
+    type: [ Card ]
+    description: The card to check.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if the card is currently an Xyz Monster, `false` otherwise.
+status:
+  index: stable
+tags: [ card-check, card-type-related ]
diff --git a/api/functions/Card/RemoveCounter.yml b/api/functions/Card/RemoveCounter.yml
index ee8d7181..4fad8f01 100644
--- a/api/functions/Card/RemoveCounter.yml
+++ b/api/functions/Card/RemoveCounter.yml
@@ -1,24 +1,28 @@
 ---!function
 name: RemoveCounter
 namespace: Card
-description: >-
-  Removes a number (int count) of the specified counter (int countertype) from a card (Card c), with reason described by (int reason)
+description: &desc Removes any amount of a specified counter from a card.
+summary: *desc
 status:
   index: stable
 parameters:
   - name: c
     type: [ Card ]
-    description: (To be added)
+    description: The card to remove counters from.
   - name: player
     type: [ int ]
-    description: (To be added)
+    description: The player removing the counters.
   - name: countertype
     type: [ int ]
-    description: (To be added)
+    description: The type of counter to remove.
   - name: count
     type: [ int ]
-    description: (To be added)
+    description: The amount of counters to remove.
   - name: reason
     type: [ int ]
-    description: (To be added)
-tags: [ under-construction ]
+    description: Composite [Reason](/api/enums/Reason) value describing why the counters are being removed.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if at least 1 counter was successfully removed, `false` otherwise.
+tags: [ counters-related ]
diff --git a/api/functions/Card/UpdateAttack.yml b/api/functions/Card/UpdateAttack.yml
index 1168e8fb..523b25ca 100644
--- a/api/functions/Card/UpdateAttack.yml
+++ b/api/functions/Card/UpdateAttack.yml
@@ -1,26 +1,34 @@
 ---!function
 name: UpdateAttack
 namespace: Card
-description: >-
-  Applies an ATK change to card c, equal to int amount. If the reset values (int reset) are not provided, the default is RESET_EVENT (+RESETS_STANDARD_DISABLE , if rc == c, or just +RESETS_STANDARD). If the reason card rc is not provided, uses as default card c. Returns the amount of ATK successfully changed.
+description: Increases the ATK of a card by a specified value (or decreases it if the value is negative).
+summary: Increases (or decreases) the ATK of a card.
 status:
   index: stable
 parameters:
   - name: c
     type: [ Card ]
-    description: (To be added)
+    description: The card to update the ATK of.
   - name: amount
     type: [ int ]
-    description: (To be added)
+    description: >-
+      The value to add to the card's current ATK.
+      Can be negative to decrease the card's ATK.
   - name: reset
     type: [ int ]
-    description: (To be added)
+    description: Composite [Reset](/api/enums/Reset) value describing when the ATK change stops applying.
     required: false
   - name: rc
     type: [ Card ]
-    description: (To be added)
+    description: The card causing the ATK change.
     required: false
+    defaultValue: c
+  - name: reset_count
+    type: [ int ]
+    description: How many times `reset` must happen for the ATK change to stop applying.
+    required: false
+    defaultValue: 1
 returns:
   - type: [ int ]
-    description: (To be added)
-tags: [ under-construction ]
+    description: The amount of ATK successfully changed (the difference between the card's new ATK and its previous ATK).
+tags: [ atk-related, registers-effect ]
diff --git a/api/functions/Card/UpdateDefense.yml b/api/functions/Card/UpdateDefense.yml
index 1c67adf4..be6e224a 100644
--- a/api/functions/Card/UpdateDefense.yml
+++ b/api/functions/Card/UpdateDefense.yml
@@ -1,26 +1,34 @@
 ---!function
 name: UpdateDefense
 namespace: Card
-description: >-
-  Applies a DEF change to card c, equal to int amount. If the reset values (int reset) are not provided, the default is RESET_EVENT (+RESETS_STANDARD_DISABLE , if rc == c, or just +RESETS_STANDARD). If the reason card rc is not provided, uses as default card c. Returns the amount of DEF successfully changed.
+description: Increases the DEF of a card by a specified value (or decreases it if the value is negative).
+summary: Increases (or decreases) the DEF of a card.
 status:
   index: stable
 parameters:
   - name: c
     type: [ Card ]
-    description: (To be added)
+    description: The card to update the DEF of.
   - name: amount
     type: [ int ]
-    description: (To be added)
+    description: >-
+      The value to add to the card's current DEF.
+      Can be negative to decrease the card's DEF.
   - name: reset
     type: [ int ]
-    description: (To be added)
+    description: Composite [Reset](/api/enums/Reset) value describing when the DEF change stops applying.
     required: false
   - name: rc
     type: [ Card ]
-    description: (To be added)
+    description: The card causing the DEF change.
     required: false
+    defaultValue: c
+  - name: reset_count
+    type: [ int ]
+    description: How many times `reset` must happen for the DEF change to stop applying.
+    required: false
+    defaultValue: 1
 returns:
   - type: [ int ]
-    description: (To be added)
-tags: [ under-construction ]
+    description: The amount of DEF successfully changed (the difference between the card's new DEF and its previous DEF).
+tags: [ def-related, registers-effect ]
diff --git a/api/functions/Cost/Choice.yml b/api/functions/Cost/Choice.yml
new file mode 100644
index 00000000..7690da56
--- /dev/null
+++ b/api/functions/Cost/Choice.yml
@@ -0,0 +1,16 @@
+---!function
+name: Choice
+namespace: Cost
+description: Creates a baseline [cost function](/api/types/EffectCost) that gives the player a choice between different baseline cost functions for the same effect (e.g. ["Starliege Lord Galaxion"](https://yugipedia.com/wiki/Starliege_Lord_Galaxion)).
+summary: Creates a cost function that gives the player a choice between different costs.
+status:
+  index: stable
+parameters:
+  - name: ...
+    type: [ table ]
+    description: >-
+      Any amount of choices represented by tables in the form {base [cost function](/api/types/EffectCost), effect description, additional check function} (e.g. `{Cost.DetachFromSelf(1),aux.Stringid(id,0),s.extracheck}`).
+      The index of the player's choice will be set as the effect's [label](/api/functions/Effect/SetLabel).
+returns:
+  - type: [ EffectCost ]
+    description: The cost function generated based on the given parameters.
diff --git a/api/functions/Cost/HardOncePerBattle.yml b/api/functions/Cost/HardOncePerBattle.yml
new file mode 100644
index 00000000..de2e8572
--- /dev/null
+++ b/api/functions/Cost/HardOncePerBattle.yml
@@ -0,0 +1,17 @@
+---!function
+name: HardOncePerBattle
+namespace: Cost
+description: Creates a baseline [cost function](/api/types/EffectCost) used for effects that can only be activated once per battle by a player.
+summary: Creates a cost function for "hard once per battle" effects.
+status:
+  index: stable
+parameters:
+  - name: flag
+    type: [ int ]
+    description: The value of the flag to register to the Duel.
+returns:
+  - type: [ EffectCost ]
+    description: The cost function generated based on the given parameters.
+suggestedLinks:
+  - name: Cost.SoftOncePerBattle
+    link: /api/functions/Cost/SoftOncePerBattle
diff --git a/api/functions/Cost/HintSelectedEffect.yml b/api/functions/Cost/HintSelectedEffect.yml
new file mode 100644
index 00000000..726549da
--- /dev/null
+++ b/api/functions/Cost/HintSelectedEffect.yml
@@ -0,0 +1,39 @@
+---!function
+name: HintSelectedEffect
+namespace: Cost
+description: A baseline [cost function](/api/types/EffectCost) used for effects that need to display which effect was activated (e.g. ["Exosister Gibrine"](https://yugipedia.com/wiki/Exosister_Gibrine)).
+summary: Cost function for effects that need to display which effect was activated.
+status:
+  index: stable
+parameters:
+  - name: e
+    type: [ Effect ]
+    description: The effect being activated.
+  - name: tp
+    type: [ int ]
+    description: The player activating the effect.
+  - name: eg
+    type: [ Group ]
+    description: A group of cards associated to the event that prompted the effect activation. The specifics of this group vary depending on the [event code](/api/enums/Event).
+  - name: ep
+    type: [ int ]
+    description: The player associated to the event that prompted the effect activation.
+  - name: ev
+    type: [ Group ]
+    description: A value associated to the event that prompted the effect activation. The specifics of this value vary depending on the event code.
+  - name: re
+    type: [ Effect ]
+    description: The effect that caused the event that prompted the effect activation.
+  - name: r
+    type: [ int ]
+    description: Composite [Reason](/api/enums/Reason) value of the event that prompted the effect activation.
+  - name: rp
+    type: [ int ]
+    description: The player that caused the event that prompted the effect activation.
+  - name: chk
+    type: [ int ]
+    description: Must be `0` when checking if the cost can be paid, and `1` when performing the cost.
+returns:
+  - type: [ bool ]
+    description: If `chk` is `0`, returns `true` if the cost can be paid.
+    guaranteed: false
diff --git a/api/functions/Cost/RemoveCounterFromField.yml b/api/functions/Cost/RemoveCounterFromField.yml
new file mode 100644
index 00000000..a1903431
--- /dev/null
+++ b/api/functions/Cost/RemoveCounterFromField.yml
@@ -0,0 +1,17 @@
+---!function
+name: RemoveCounterFromField
+namespace: Cost
+description: Creates a baseline [cost function](/api/types/EffectCost) for effects that remove a counter(s) from the activating player's field as cost, such as `You can remove 1 Spell Counter from your field;` (e.g. ["Arcanite Magician"](https://yugipedia.com/wiki/Arcanite_Magician)).
+summary: Creates a cost function for effects that remove a counter from the field.
+status:
+  index: stable
+parameters:
+  - name: counter_type
+    type: [ int ]
+    description: The type of counter to remove.
+  - name: count
+    type: [ int ]
+    description: The amount of counters to remove.
+returns:
+  - type: [ EffectCost ]
+    description: The cost function generated based on the given parameters.
diff --git a/api/functions/Cost/RemoveCounterFromSelf.yml b/api/functions/Cost/RemoveCounterFromSelf.yml
new file mode 100644
index 00000000..d4413340
--- /dev/null
+++ b/api/functions/Cost/RemoveCounterFromSelf.yml
@@ -0,0 +1,17 @@
+---!function
+name: RemoveCounterFromSelf
+namespace: Cost
+description: Creates a baseline [cost function](/api/types/EffectCost) used for effects that remove a counter(s) from the activating card itself as cost, such as `You can remove 1 Spell Counter from this card;` (e.g. ["Breaker the Magical Warrior"](https://yugipedia.com/wiki/Breaker_the_Magical_Warrior)).
+summary: Creates a cost function for effects that remove a counter from the card itself.
+status:
+  index: stable
+parameters:
+  - name: counter_type
+    type: [ int ]
+    description: The type of counter to remove.
+  - name: count
+    type: [ int ]
+    description: The amount of counters to remove.
+returns:
+  - type: [ EffectCost ]
+    description: The cost function generated based on the given parameters.
diff --git a/api/functions/Cost/SelfChangePosition.yml b/api/functions/Cost/SelfChangePosition.yml
new file mode 100644
index 00000000..2f6890f2
--- /dev/null
+++ b/api/functions/Cost/SelfChangePosition.yml
@@ -0,0 +1,14 @@
+---!function
+name: SelfChangePosition
+namespace: Cost
+description: Creates a baseline [cost function](/api/types/EffectCost) used for effects that change the battle position of the activating card itself as cost, such as `You can change this face-down card to face-up Defense Position;` (e.g. ["Enneacraft - Atori.MAR"](https://yugipedia.com/wiki/Enneacraft_-_Atori.MAR)).
+summary: Creates a cost function for effects that change the card's own position as cost.
+status:
+  index: stable
+parameters:
+  - name: position
+    type: [ int ]
+    description: The position to change the card to.
+returns:
+  - type: [ EffectCost ]
+    description: The cost function generated based on the given parameters.
\ No newline at end of file
diff --git a/api/functions/Cost/SoftOncePerBattle.yml b/api/functions/Cost/SoftOncePerBattle.yml
new file mode 100644
index 00000000..8e11b901
--- /dev/null
+++ b/api/functions/Cost/SoftOncePerBattle.yml
@@ -0,0 +1,17 @@
+---!function
+name: SoftOncePerBattle
+namespace: Cost
+description: Creates a baseline [cost function](/api/types/EffectCost) used for effects that can only be activated once per battle *per card*, e.g. ["Lavalval Ignis"](https://yugipedia.com/wiki/Lavalval_Ignis).
+summary: Creates a cost function for "soft once per battle" effects.
+status:
+  index: stable
+parameters:
+  - name: flag
+    type: [ int ]
+    description: The value of the flag to register to the card.
+returns:
+  - type: [ EffectCost ]
+    description: The cost function generated based on the given parameters.
+suggestedLinks:
+  - name: Cost.HardOncePerBattle
+    link: /api/functions/Cost/HardOncePerBattle
diff --git a/api/functions/Duel/GetReasonEffect.yml b/api/functions/Duel/GetReasonEffect.yml
new file mode 100644
index 00000000..9d4f54b1
--- /dev/null
+++ b/api/functions/Duel/GetReasonEffect.yml
@@ -0,0 +1,10 @@
+---!function
+name: GetReasonEffect
+namespace: Duel
+description: Returns the [effect](/api/types/Effect) that the simulator considers as the "current effect", typically the effect being currently checked, activated, resolved, or applied.
+summary: Returns the "current effect".
+status:
+  index: stable
+returns:
+  - type: [ Effect ]
+    description: The current effect.
diff --git a/api/functions/Duel/GetReasonPlayer.yml b/api/functions/Duel/GetReasonPlayer.yml
new file mode 100644
index 00000000..b78d351d
--- /dev/null
+++ b/api/functions/Duel/GetReasonPlayer.yml
@@ -0,0 +1,10 @@
+---!function
+name: GetReasonPlayer
+namespace: Duel
+description: Returns the [effect](/api/types/Effect) that the simulator considers as the "current player", typically the player currently performing an action.
+summary: Returns the "current player".
+status:
+  index: stable
+returns:
+  - type: [ int ]
+    description: The "current player".
diff --git a/api/functions/Duel/GetTargetGroup.yml b/api/functions/Duel/GetTargetGroup.yml
new file mode 100644
index 00000000..1fabd114
--- /dev/null
+++ b/api/functions/Duel/GetTargetGroup.yml
@@ -0,0 +1,31 @@
+---!function
+name: GetTargetGroup
+namespace: Duel
+description: >-
+  Returns cards from given locations that match a filter and can be targeted by the ["current effect"](/api/functions/Duel/GetReasonEffect).
+  Essentially [`Duel.GetMatchingGroup`](/api/functions/Duel/GetMatchingGroup), but implicitly checks for targetable cards.
+summary: Returns targetable cards from given locations that match a filter.
+status:
+  index: stable
+parameters:
+  - name: filter
+    type: [ FilterFunction ]
+    description: A function that must return `true` for a card to be included.
+  - name: player
+    type: [ int ]
+    description: The player from whose perspective the `s` and `o` locations will be based on.
+  - name: s
+    type: [ int ]
+    description: Composite [Location](/api/enums/Location) value representing locations on `player`'s side of the Duel.
+  - name: o
+    type: [ int ]
+    description:  Composite [Location](/api/enums/Location) value representing locations on `player`'s opponent's side of the Duel.
+  - name: ex
+    type: [ Group, Card, nil ]
+    description: Cards to exclude from the returned group even if they match the filter.
+  - name: ...
+    type: [ any ]
+    description: Additional arguments to be passed as additional arguments to `filter`.
+returns:
+  - type: [ Group ]
+    description: The group of cards from the given locations that fulfill `filter` and can be targeted by the "current effect".
\ No newline at end of file
diff --git a/api/functions/Effect/HasDetachCost.yml b/api/functions/Effect/HasDetachCost.yml
new file mode 100644
index 00000000..f6f07858
--- /dev/null
+++ b/api/functions/Effect/HasDetachCost.yml
@@ -0,0 +1,15 @@
+---!function
+name: HasDetachCost
+namespace: Effect
+description: Checks if an [Effect](/api/types/Effect) has a cost that detaches an Xyz Material(s) from the activating card itself.
+summary: Checks if an effect has a cost that detaches Xyz Materials from itself.
+status:
+  index: stable
+parameters:
+  - name: e
+    type: [ Effect ]
+    description: The effect to check the cost of.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if `e` has a cost that detaches Xyz Materials from the activating card, `false` otherwise.
diff --git a/api/functions/Effect/HasSelfDiscardCost.yml b/api/functions/Effect/HasSelfDiscardCost.yml
new file mode 100644
index 00000000..a1d03ac6
--- /dev/null
+++ b/api/functions/Effect/HasSelfDiscardCost.yml
@@ -0,0 +1,15 @@
+---!function
+name: HasSelfDiscardCost
+namespace: Effect
+description: Checks if an [Effect](/api/types/Effect) has a cost that discards the activating card itself.
+summary: Checks if an effect has a cost that discards the activating card itself.
+status:
+  index: stable
+parameters:
+  - name: e
+    type: [ Effect ]
+    description: The effect to check the cost of.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if `e` has a cost that discards the activating card, `false` otherwise.
diff --git a/api/functions/Effect/HasSelfToGraveCost.yml b/api/functions/Effect/HasSelfToGraveCost.yml
new file mode 100644
index 00000000..d7cce4ce
--- /dev/null
+++ b/api/functions/Effect/HasSelfToGraveCost.yml
@@ -0,0 +1,15 @@
+---!function
+name: HasSelfToGraveCost
+namespace: Effect
+description: Checks if an [Effect](/api/types/Effect) has a cost that discards the activating card itself to the GY.
+summary: Checks if an effect has a cost that sends the activating card itself to the GY.
+status:
+  index: stable
+parameters:
+  - name: e
+    type: [ Effect ]
+    description: The effect to check the cost of.
+returns:
+  - type: [ bool ]
+    description: >-
+      `true` if `e` has a cost that sends the activating card to the GY, `false` otherwise.
diff --git a/api/functions/Link/AddProcedure.yml b/api/functions/Link/AddProcedure.yml
index 255ca080..902f4207 100644
--- a/api/functions/Link/AddProcedure.yml
+++ b/api/functions/Link/AddProcedure.yml
@@ -37,3 +37,10 @@ parameters:
     required: false
     defaultValue: |-
         The default string 1174: "Link Summon".
+  - name: spcon
+    type: [ function]
+    description: >-
+        An additional check equivalent to a Special Summon condition for the Link Monster (e.g. "Lib the World Key Blademaster").
+        Its signature is `(e,se,sp,st)` like the value function of a typical `EFFECT_SPSUMMON_CONDITION` effect.
+    required: false
+    defaultValue: nil