A plaintiff lawyer is the attorney who represents the suing party in a lawsuit. In fact, this is exactly what a plaintiff lawyer pursues, he or she represents the persons who have been damaged in the financial or physical form and are suing for the purpose. So, if in a hospital some inappropriate medication is given to you as an individual, or due to the negligence of the surgeon severe accident occurs with your family member, then you can take the services of a plaintiff lawyer.
It would definitely not be possible for you to pay the expenses in such a situation. In fact, for cases like injury or death of a construction worker, accident on the road, abuse of a nursing home resident, the suing party is most of the time not able to afford the fees.
Since, this should not leave them from legal rights or the right to seek compensation. Hence, the plaintiff lawyer does not charge such people of any money upfront. It is them, who take care of all the expenses for years of legal pursuit. So whether they have to pay the investigators, the expert witnesses or the paper work everything is pursued by their finances comprehensively. Once the case is won by the suing party, a part of the settlement is given to the plaintiff lawyer as decided in advance.
This category of lawyer has immense faith in the jury. In fact, he or she also trusts their own capability. Hence, they are able to take such risks in the best possible way!