Q: Is there an "infield fly" rule? Are fielders permitted to intentionally let kicked balls drop in order to attempt a double play?
A: There is no "infield fly" rule in the WAKA rules, nor any countermeasure against fielders who find it to their tactical advantage to let a ball drop rather than catch it.
The infield fly rule as seen in MLB has a fairly intricate set of criteria, both in terms of the situation (e.g., number of outs and base runners), as well as the definition of the "ordinary effort" required to make a catch. When it comes to kickball, an amateur social sport, WAKA has found that "ordinary effort" is not really an applicable concept, and keeping rules as simple as possible for volunteer Referees to call is a benefit to everyone involved. Kickers are therefore advised to try and avoid kicking pop flies in the immediate vicinity of bases to which their runners will be heading.