Can you choose the order your own triggered abilities go on the stack when multiple triggers happen simultaneously?

When two or more triggered abilities trigger at the same time and are controlled by the same player, that player chooses the order in which those abilities are placed onto the stack (CR 603.3b). Because the stack is last-in, first-out, the ability placed on the stack last will resolve first.

If triggers from multiple players happen simultaneously, the active player (the player whose turn it is) orders and places all of their triggers first, then each other player in turn order does the same (CR 603.3b). Each player only controls the ordering of their own triggers.

It is important to note that this only applies to triggers that happen at the same time. If one trigger causes another to trigger, they do not go on the stack simultaneously — the new trigger waits until a player would receive priority and then goes on top (CR 603.3).

Example: You control both Purphoros, God of the Forge and Mana Echoes, and you cast a creature spell that resolves, triggering both simultaneously. You choose whether Purphoros's damage trigger or Mana Echoes's mana trigger goes on the stack last (and thus resolves first) — letting you, for instance, use the mana before dealing damage if that matters.

This ordering choice can be strategically significant, so always consider which resolution order benefits you most before declaring the stack order to your opponent.