If something comes into play, it starts to have a use or an effect in a particular situation, and if it is brought into play, it is given a use or an effect.

In the summer months a different set of climatic factors come into play. 在夏季的几个月中，一系列不同的气候因素开始起作用。

All the resources and staff available were brought into play to cope with the crisis. 所有可用的资源和人力都被投入进来应对这场危机。