Terms and Conditions is correct.
"Under field conditions" is more idiomatic.
To what, under which conditions?
no conditions
The conditions were BAD!
what conditions do you mean
living conditions were horrid!!!
The "Goldilocks conditions" refer to conditions that are just right for a particular outcome. Three conditions for goldilocks conditions could include: 1) not too hot, 2) not too cold, and 3) optimal environment for growth or development.
the conditions are:cold weather
Business conditions in general
pediatrician work conditions
Very good conditions!