When multiple triggered abilities trigger at the same time, they don't all go on the stack simultaneously — they are placed on the stack one at a time. The active player (the player whose turn it is) puts all of their simultaneously triggered abilities on the stack in whatever order they choose, then the non-active player does the same. The last ability placed on the stack will resolve first (LIFO order). This is governed by CR 603.3b.
This ordering choice is significant because it lets you control the sequence in which effects happen. For example, if you control a trigger that draws a card and another that deals damage, you can choose which resolves first to potentially use the drawn card before damage is dealt.
However, if the triggers are controlled by different players, each player independently orders their own triggers. The non-active player's triggers end up on top (resolving first) if both players have simultaneous triggers, because the active player places theirs first and the non-active player places theirs on top — but each player still freely orders their own group (CR 603.3b).
Concrete example: It's your turn and two of your creatures die simultaneously, triggering both a 'draw a card' ability and a 'create a 1/1 token' ability. You may choose to put the draw trigger on the stack last (so it resolves first), drawing a card before the token is created — or vice versa. The choice is entirely yours.
Note that if an effect specifically says triggers go on the stack in a particular order, that overrides the default rule. But absent such instructions, CR 603.3b gives each controller free ordering of their own simultaneous triggers.
Unofficial fan resource — not affiliated with or endorsed by Wizards of the Coast. Answers are AI-generated estimates grounded in the Comprehensive Rules and are not a substitute for an official judge. Verify anything match-critical.