B · Engine & Sequencing · §7
The kill is an effect, not a cost — Hook is the higher-ceiling but interactable outlet.
Resolution timeline
From the guide — §7 Baited Hook: Rules & Tactical Implications
The current Hook text kills a friendly target, looks at the top five cards, and allows you to play an eligible unit with Might up to one greater than the killed unit while ignoring its cost.◆src
When you activate Hook: you choose the friendly unit; the opponent receives an opportunity to react; Hook resolves; it attempts to kill that unit; its actual Might at that time determines the maximum legal hit.
The opponent can therefore remove the target, move it, prevent its death, reduce its Might, or otherwise make it an invalid or less valuable conversion.
This makes Hook the deck’s higher-ceiling but interactable outlet.
Hook uses the Might of the unit when Hook kills it, after relevant continuous and arithmetic modifications — not only printed Might.
When Hook kills a Deathknell unit and plays a new unit: the killed unit’s Deathknell is created; Hook continues resolving; the new unit is played; the new unit’s play trigger resolves; the original Deathknell resolves afterward. This matters with Harnessed Dragon, Watcher, Ruined Rex and Glasc.
Example — Hook kills Ruined Rex and finds Harnessed Dragon: Rex’s Deathknell is queued → Dragon is played → Dragon’s kill trigger resolves → Rex’s four damage resolves afterward. You can assign the two effects to different targets and avoid wasting removal.
Even when Hook is virtually guaranteed to find a legal unit, it is not guaranteed to find the desired upgrade. The relevant distinction is legal hit rate versus premium tier hit rate — and it should drive whether you can afford to sacrifice a strategically important body.