Must You Process an [All Turns] Effect in Full? Mandatory vs. Optional
"After that" often splits an effect into a forced half and a free half
When an [All Turns] effect triggers — BT25-058 Callismon, BT25-077 Bacchusmon — players constantly ask: do I have to process ALL of it, or can I skip parts? Based on Comprehensive Rules 15-1-5, 15-9-1, and 15-9-2, here's how to tell mandatory from optional at a glance.
The principle: non-optional effects execute whenever possible
Comprehensive Rules 15-1-5:
"If an effect is mandatory and not optional, its processing must be performed whenever possible."
Once an effect triggers and activates, its mandatory parts aren't up to you — you can't choose to skip them.
Its optional parts, on the other hand, are yours to take or leave.
"If an effect is mandatory and not optional, its processing must be performed whenever possible."
Once an effect triggers and activates, its mandatory parts aren't up to you — you can't choose to skip them.
Its optional parts, on the other hand, are yours to take or leave.
Telling them apart by the sentence ending (15-9-1, 15-9-2)
Read the verbs:
- Plain imperatives — "delete...", "place...", "trash..." → **mandatory processing** (15-9-1-2: the player must choose to execute it)
- "May ..." / "can ..." endings → **optional processing** (15-9-2-2: the player can choose whether to execute it)
A single effect often mixes both. Check each clause, one at a time.
- Plain imperatives — "delete...", "place...", "trash..." → **mandatory processing** (15-9-1-2: the player must choose to execute it)
- "May ..." / "can ..." endings → **optional processing** (15-9-2-2: the player can choose whether to execute it)
A single effect often mixes both. Check each clause, one at a time.
Example 1: Mandatory and optional in one effect (BT25-058 Q6347)
BT25-058 Callismon's [All Turns] effect: "When a Digimon is played or digivolves by an effect, <De-Digivolve 1> on 1 of your opponent's Digimon. After that, this Digimon may battle 1 of your opponent's Digimon."
The Q6347 verdict:
- "<De-Digivolve 1> on 1 of your opponent's Digimon" (imperative) → **mandatory**. Once triggered, it happens
- "After that, ... **may** battle ..." → **optional**. Your call
So the shape is: the De-Digivolve is forced on you; the battle is a choice.
The Q6347 verdict:
- "<De-Digivolve 1> on 1 of your opponent's Digimon" (imperative) → **mandatory**. Once triggered, it happens
- "After that, ... **may** battle ..." → **optional**. Your call
So the shape is: the De-Digivolve is forced on you; the battle is a choice.
Example 2: The "after that" half can be the mandatory one (BT25-077 Q6378)
BT25-077 Bacchusmon's [All Turns] effect: "When a Digimon is played or digivolves, you may suspend 1 Digimon. After that, if it was played or digivolved by an effect, delete 1 of your opponent's Digimon with the lowest DP."
The Q6378 verdict:
- "You may suspend 1 Digimon" → optional
- "After that, if it was played or digivolved by an effect, delete..." (imperative) → **mandatory**
So if the play/digivolution came from an effect, the deletion MUST happen — declining isn't on the menu.
- Basis: 15-1-5 (non-optional effects execute whenever possible), 15-9-1-2 (mandatory processing must be executed), 15-6-1 (processing with an "if" condition executes when the condition holds)
The Q6378 verdict:
- "You may suspend 1 Digimon" → optional
- "After that, if it was played or digivolved by an effect, delete..." (imperative) → **mandatory**
So if the play/digivolution came from an effect, the deletion MUST happen — declining isn't on the menu.
- Basis: 15-1-5 (non-optional effects execute whenever possible), 15-9-1-2 (mandatory processing must be executed), 15-6-1 (processing with an "if" condition executes when the condition holds)
[All Turns] timing and use counts
The other big [All Turns] point: its breadth.
- It triggers during your turn AND your opponent's turn (15-16-9)
- With a [Once Per Turn] limit, that's once per EACH turn — not once total (15-14-1-1)
- The count resets when the turn passes
BT25-058 is [All Turns] [Once Per Turn], so it can activate once during your turn and once more during your opponent's — up to twice per full round.
- It triggers during your turn AND your opponent's turn (15-16-9)
- With a [Once Per Turn] limit, that's once per EACH turn — not once total (15-14-1-1)
- The count resets when the turn passes
BT25-058 is [All Turns] [Once Per Turn], so it can activate once during your turn and once more during your opponent's — up to twice per full round.
Relevant Comprehensive Rules sections
Key point Whether an [All Turns] effect is all-mandatory or partly skippable is written in the verbs: imperative = forced, "may" = your choice. "After that" frequently splits one effect into a forced half and a free half — read each clause's ending, every time.