**1. Introduction**

Automated liquid handling has become an indispensable tool in drug discovery, particular‐ ly in screening campaigns ranging millions of compounds. Intense innovations of these de‐ vices go hand in hand with the progression towards assay miniaturization, accelerating dramatically the discovery of drug candidates and chemical probes for querying biological systems. The advancement in this technology is driven in large part by much impetus in cost reduction and efficiency. In addition to increased throughput, streamlining screening opera‐ tions using automated fluid devices ensures consistency and reliability while avoiding hu‐ man error.

In this chapter, we provide a general overview of existing liquid handlers, with emphasis on their strengths and limitations. Notably, we discuss practical considerations in the imple‐ mentation of these devices, methods to discern performance quality and potential sources of error.
