No, you will not have to pay to use Java.
According to the OTN license agreement - which will apply to Java Runtime and Development Kit - these uses are free:
- Personal Use,
- Development Use,
- Oracle Approved Product Use, and/or
- Oracle Cloud Infrastructure Use.
We are interested in Personal use:
“Personal Use” refers to an Individual's use of the Programs solely on a desktop or laptop computer under such Individual's control only to run Personal Applications.
“Personal Applications” refers to Applications designed for individual personal use only, such as games or personal productivity tools.
Which would cover playing games.
And Development Use:
“Development Use” refers to Your internal use of the Programs to develop, test, prototype and demonstrate Your Applications. For purposes of clarity, the “to develop” grant includes using the Programs to run profilers, debuggers and Integrated Development Environments (IDE Tools) where the primary purpose of the IDE Tools is profiling, debugging and source code editing Applications.
Which would cover developing games.
When you sell a game made with Java, you are not selling the Java Runtime nor the Java Development Kit. Instead, the end user is supposed to get them that on their own.
However, it appears that using the Java Runtime or the Development Kit on a server solution is not free (with exceptions). Please refer to the linked license for details. There is no replacement for reading the actual license.
By the way, OpenJDK would allow you to use Java, and it is under GPL version 2 (The GPL are free software licences according to the Free Software Foundation, and are approved by the Open Source Initiative).