Can Rumble Hothead's conquer trigger be activated when there are no mechs in the graveyard, with the intention of ordering Zaun Warrens' trigger first to discard a mech from hand, then targeting that mech with Rumble's effect on resolution?

Question

Accepted Answer

Assuming Rumble Hothead’s conquer ability is a normal triggered ability that does not itself require a Mech to be present as part of its triggering condition, you may put that trigger on the chain even if there are currently no Mechs in your Trash. If you control both triggers (the Zaun Warrens battlefield conquer and Rumble Hothead’s conquer trigger), you can order Zaun Warrens to resolve first so it discards a Mech from hand to Trash, and then finalize/resolve Rumble Hothead’s trigger targeting that newly-trashed Mech—provided the Rumble trigger’s legal target is chosen/finalized after Zaun Warrens resolves and is legal at finalization. See assumptions below.

Yes — under the defensible assumptions below, you can place Rumble Hothead’s conquer trigger on the chain when you conquer even if there are no Mechs in your Trash at that moment, arrange Zaun Warrens to resolve first to discard a Mech from hand, and then finalize/resolve Rumble Hothead’s trigger targeting that Mech in the Trash. This relies on the fact that trigger finalization (choices/targets/costs) happens after the trigger is added to the chain, so a later-resolving item (Zaun Warrens) can create a legal target for an earlier-added trigger that is finalized afterward [FAQ:unleashed#2]. However, if Rumble Hothead’s trigger has a built-in precondition that requires a Mech to already be in the Trash at the moment it would trigger, it would not trigger and this line of play is not possible [FAQ:unleashed#2]. Also, you may not attempt to pay any costs during finalization that would deterministically make the finalization illegal [357.3].

Conquer occurs at the battlefield. Both "When you conquer here" effects see the conquer and become pending triggers (they are added to the chain as Pending Items) [FAQ:unleashed#2]. When adding pending triggers, the controller(s) order their triggers (assumption: you control both and can order them so Zaun Warrens resolves before Rumble Hothead). Finalize the topmost pending item first: resolve Zaun Warrens. Its effect performs "discard 1, then draw 1," causing you to discard a Mech from hand to your Trash (creating a legal target) and then draw 1. Now finalize the next pending item (Rumble Hothead). During finalization you make any choices/targets and pay costs required by that triggered ability—at this point the Mech in your Trash is a legal target, so you may choose it and the trigger can resolve successfully [FAQ:unleashed#2]. If at finalization there were no legal targets and the trigger required a target to be chosen, you would be unable to finalize it (or it would be illegal to place it on the chain if its wording made the target requirement part of the trigger condition) [FAQ:unleashed#2] [357.3].

If Rumble Hothead’s trigger text itself contains an explicit precondition like "When you conquer here, if a Mech is in your Trash, ..." then it will not trigger at all when there are no Mechs in the Trash and this line does not work [FAQ:unleashed#2]. If Rumble Hothead’s trigger requires a target at the moment the trigger is created (rare wording), and such a requirement is part of the trigger condition rather than an effect choice, you could not place that trigger when there are no legal targets. The provided rules excerpt does not include an explicit rule text for 'must have legal target to add trigger' so confirm the exact wording of the Rumble card. If the triggers are controlled by different players, the ordering of pending triggers may not let you choose Zaun Warrens to go first — ordering rules for multiple players' triggers are not in the provided excerpt, so that could change the outcome. If there are replacement effects or other intervening triggers that change where the discarded Mech goes (e.g., replacement that causes discard to be prevented or the card to be placed elsewhere), then the target might not be created as expected. Replacement effects inherit modifications and can change events—see [375].

What matters for this line of play is when choices (targets/costs) for a triggered ability are made versus when the triggers are added to the chain. The rules and clarifications explain that the trigger's condition causes a pending chain item to be created, and that choices and costs tied to the trigger are handled when that pending item is finalized (the finalization process where players make choices and pay costs) [FAQ:unleashed#2]. That means a triggered ability that does not require its target to exist as part of its trigger condition can be placed on the chain even if a legal target does not yet exist; you will pick targets when you finalize that trigger.

Applying that here: Zaun Warrens reads "When you conquer here, discard 1, then draw 1." If both it and Rumble Hothead’s "When you conquer here" triggers are pending, you (assuming you control both) can arrange the pending items so Zaun Warrens resolves first. When Zaun Warrens resolves it discards a card from your hand into the Trash — that discard can put a Mech into your Trash and thereby create a legal target. After Zaun Warrens resolves, you finalize/resolve Rumble Hothead’s trigger; at finalization you choose targets and pay costs, and now the Mech in Trash is a valid target, so the Rumble effect can resolve and affect that Mech.

Two important caveats: if Rumble Hothead’s ability text itself makes the presence of a Mech in Trash part of the trigger condition (for example, "When you conquer here, if you have a Mech in your Trash, ...") then it never triggers when no Mechs are in Trash, and the plan fails [FAQ:unleashed#2]. Also, you must not attempt to pay costs or make finalization choices that will deterministically be illegal later in the process [357.3]. Finally, replacement effects or other intervening effects could change where the discarded card ends up or whether it becomes a legal target; replacement effects can change events and inherit modifications [375].

Because the exact text of Rumble Hothead was not provided, I framed this ruling around the most defensible interpretation of how conquer triggers and finalization work under the provided rules. If you can paste the exact text of Rumble Hothead’s conquer ability, I can give a definitive ruling that accounts for any gating language in that ability.