In Orcs Must Die, do guardians count as traps?
As per my experience and this thread:
you can also use any weapons, magic, guardians and boom barels since they don't count as traps
So no, guardians do not count as traps. I believe barricades do not count either. If you're really ambitious, you might try for the no traps achievement at the same time, killing two birds with one stone.
Additionally, beware not to activate any of the traps in the environment because those do count as traps and will negate the achievement.