If your possession has been "adverse," you own it. Adverse possession is the only example of squatter's rights in Illinois property law.In 2a-e, check the reason you are asking the court to evict. Defendants from the property. 1. In Illinois, landlords cannot evict a tenant or force them to vacate the property without probable cause. For more information about going to court including how to fill out and file forms, call or text Illinois Court Help at 833-411-1121 or go to ilcourthelp.gov. In Illinois, a squatter must live on the property continuously for 20 years before they can make a legal claim of adverse possession. For more information about going to court including how to fill out and file forms, call or text Illinois Court Help at 833-411-1121 or go to ilcourthelp.gov. And exercised all other rights over the property that are necessary to the ownership. Find out how to fill out a written notice and give it to your tenants.