Beginning at 3rd level, players are allowed to recruit hirelings to their cause.
Hirelings are NPCs under the GM's control who are working for the PCs for material gain.
They come in two flavors, muscle or service.
Hirelings in this category are not averse to risk and would accompany PCs on hazardous duties such as tomb delving, raids and the like, though negative reactions would occur if they are repeatedly forced in very dangerous combats.
They come without equipment and expect their employer to provide initial equipment suitable to their status as fighting men/women.
These NPCs would have morale ratings, loyalty, wealth and experience tracked by the GM. Their stats would be masked however.
These hirelings provide certain duties that could fulfill an adventuring party's wants such as expert healing, cooking, equipment repairs, guide, porterage, etc. These NPCs however are risk-adverse and refuse following the party into hazardous areas. Most of them would also require added expenses if they are to provide their services on the road.
The GM would track their moral and loyalty.
For Service Hirelings, the intention to recruit them would be made a guildhall, inn or via agents depending on services needed.
A contract is agreed upon where time services required is stated and the requested payment offered. Usually the sum is paid in halves and completed when the time is up. Additional payment may be needed if there is a requirement for services on the move and possibility of contract extension.
Muscle hireling are through a different process where an effort to recruit risk-takers to join the party are made
Common methods are via agents, barkeep, advertisement and town crier if any. Interested applicants would turn up the next day and hear out the terms of the contract before agreeing or disagreeing. They come without any equipment whatsoever.
Contract terms would need to include signing on fee, living expenses, expected duration, equipment offered, wages, loot shares if any, and expected role.
Hireling loyalty would be influenced by charisma, alignment, role in party, hazards exposed, duration of current service, special services done by employer.