Hall of Legends, do you need to pay right away as a cost, or can I wait for other conquer triggers to finish before I choose to pay?

To address your question regarding Hall of Legends, the card ability reads: "When you conquer here, you may pay [1] to ready your legend."

Ruling

You must pay the cost at the time you place the ability on the chain (the finalization step). You do not pay the cost upon resolution.

According to Rule 742.1.b, Rule 383.3.b.2, and the Rules FAQ Clarification (2026-04-29), costs associated with "you may" triggered abilities are paid when the ability is placed on the chain, not when it resolves.

1. Triggering: When you conquer the battlefield, the condition is met, and you may place the ability on the chain (Rule 383.3.a).
2. Finalization: If you choose to use the ability, you must pay the [1] cost at the moment you place the ability on the chain. If you do not pay the cost, the ability is not placed on the chain.
3. Resolution: Once the ability is on the chain and resolves, the effect (readying your legend) occurs automatically. Because the cost is paid during finalization, you cannot wait for other conquer triggers to resolve before deciding whether to pay for the Hall of Legends trigger.

Summary: You must decide whether to pay the [1] cost and perform the payment at the time you place the trigger on the chain. If you have other conquer triggers, you must decide whether to pay for this ability when you choose to place it on the chain, prior to the resolution of any triggered abilities.

Note: I could not fully verify this ruling against the retrieved rules.