Do state-based actions check for a creature with 0 toughness before triggers resolve?

State-based actions (SBAs) are checked by the game at specific moments: whenever a player would receive priority, and immediately after a phase or step begins. Crucially, this check happens before any triggered abilities are placed on the stack or allowed to resolve. This is governed by CR 704.3 and CR 704.5f.

CR 704.5f states that if a creature has toughness 0 or less, it is put into its owner's graveyard. This SBA is processed as soon as the game checks, which occurs before any waiting triggered abilities can go on the stack (CR 116.5, CR 704.3).

The process is: (1) An event occurs (e.g., a spell resolves). (2) The game checks SBAs and processes all that apply simultaneously, repeating until none remain. (3) Only then are triggered abilities that fired during that event put onto the stack. (4) A player receives priority.

Example: Your opponent controls a 2/2 creature. You cast Sudden Spoiling, making all their creatures 0/2 with no abilities — wait, better example: you enchant their 1/1 with a −1/−1 aura. The creature becomes 1/0. Before any triggered abilities (like a 'when this creature dies' trigger) can resolve, the game checks SBAs, finds the 0-toughness creature, and moves it to the graveyard. The death trigger then goes onto the stack afterward.

This ordering matters because it means you cannot respond to a creature being 'about to die' from 0 toughness — it is already gone by the time anyone gets priority. CR 704.3 and 704.5f are the key rules here.