Simplify the following text for a Grade 12 native English-speaking person.
Original: Teams consist of fifteen players ( a goalkeeper , two corner backs , a full back , two wing backs , a center back , two mid fielders , two wing forwards , a center forward , two corner forwards and a full forward ) plus up to fifteen substitutes , of which five may be used .
Simplified: Teams consist of fifteen players ( a goalkeeper , two corner backs , a full back , three half backs , two mid fielders , three half forwards , two corner forwards and a full forward ) plus up to fifteen substitutes , of which five may be used .