operator
Logical
and or not
The boolean combinators are and, or, and not. They combine bool values — usually the results of comparisons — into the compound conditions an if, while, or where clause tests. Ludic spells them as words, not symbols: && and || are not operators, and a bare ! is rejected with a diagnostic pointing you to not (!= is unaffected). and binds tighter than or, so a and b or c groups as (a and b) or c; add parentheses when you mean otherwise.
Example
if pressed_key != 0 and not is_paused { apply_input() }
if current_health <= 0 or elapsed_frames > time_limit { become GameOver }