Why do some spells need to choose their targets on play and others on resolution? Can you give me examples?
Great question — the short version is: targets are always chosen when the effect goes on the Chain, never on resolution. What looks like "targeting on resolution" is actually a reflexive trigger ("Do this:") creating a separate Chain item after the first part resolves.
Default rule: targets on play
Most spells work like Gust or Fox-Fire. When you play them, you pick targets during Step 2 of playing the card (Rule 355.5–355.8). Those targets are locked in before your opponent gets a Reaction window.
Play Gust → choose which unit to bounce → opponent can react → Gust resolves and bounces that unit (or whiffs if it moved)
Same for split damage spells like Alpha Strike: you choose the targets on play, but how much damage each gets is decided on resolution (Rule 355.14.e).
Why some look like they target on resolution: Reflexive Triggers
Cards with "Do this:" or "Do one of the following:" create a new triggered ability on the Chain after the first part finishes resolving (Rule 386–388). That new ability chooses its own targets when it goes on the Chain — which happens after the original spell resolves.
Example: Dragon's Rage
- You play Dragon's Rage, targeting an enemy unit and choosing a destination — targets chosen on play.
- It resolves: the unit moves.
- A new reflexive trigger goes on the Chain ("Do this: choose another enemy unit at its destination...") — this trigger targets on its own finalization, not on Dragon's Rage's cast.
So it feels like the second target was chosen "on resolution" of Dragon's Rage, but mechanically it's a separate Chain item with its own targeting step.
Another example: Fox-Fire-style "Do this N times" — each repetition creates its own reflexive trigger, and each one targets independently when it finalizes.
One more nuance: effect choices vs. targets
Choices that are part of the effect (not costs or targeting) happen on resolution. For example, a card that says "Deal 3 to a unit, then discard 1" — the unit was targeted on play, but which card to discard is chosen on resolution (FAQ #6214). But that's not targeting — it's a choice within the effect.
TL;DR: If it says "Do this:" → the "second target" is chosen by a separate trigger on its own finalization. Everything else targets when played.