Is it safe to eat that leftover chicken?

Situation Safe time at room temperature*
Cooked meat (including chicken) Up to 2 hours maximum before refrigerating.
If the ambient temperature is high (> ~90°F / 32°C) Only 1 hour maximum outdoors.
“Room temperature” here refers to what is felt in many kitchens or indoor environments: moderate, not super hot.

Once this safety period has expired, the meat should be dumped, even if it smells or looks good. Appearance and odor are unreliable indicators of bacterial contamination.