1. Landowners have very minimal exposure even without a waiver. See the Texas Recreational Use Statute. http://www.statutes.legis.state.tx.us/Docs/CP/htm/CP.75.htm
Importantly, hunting has one of the lowest rates of injury of any sporting activity, lower than even bowling and golf. http://www.nssf.org/newsroom/releases/show.cfm?PR=120511.cfm&path=2011
2. Most waivers I've seen are so poorly done that they are close to meaningless and miss some of the major issues. While landowners have minimal exposure, lessees that act as a "lease manager" may face some risks discussed below, as they may or may not have the benefit of the Recreational Use Statute depending on the issue. The statute provides immunity against natural conditions of the land, not man-made structures and equipment. If you are really worried about some major liability exposure, then this is not a do it yourself project from google on the internet. Like most things in law, it is far less expensive to involve a lawyer on the front end before a problem arises. Lawyers that specialize in defending personal injury cases, typically hired by insurance companies, are the ones to seek for advice. Real estate lawyers are a second choice, but often not up to speed on tort liability or the waivers needed for something such as a hunting lease.
3. Irrespective of liability, landowners and those on leases should try to make reasonable efforts to inform guests about hazards that are not "open and obvious."
Examples would be of areas known to be subject to cave ins, areas where toxic chemicals have been dumped, typically from oil and gas operations, and most importantly, poor quality blinds and stands, see next item.
4. By far the most dangerous thing likely to be encountered on a hunting lease is an ATV/UTV and stands/blines. ATV's are incredibly dangerous, regularly producing permanent paralyzing injuries, and yet kids are routinely given keys and turned loose. In 2013, ATV's caused almost 100,000 injuries requiring trips to the hospital, 25% i.e. over 25,000 per year, of which involved children. See page 2: http://www.cpsc.gov/Global/Research-and-...s--Injuries.pdf
Second place for dangerous are falls from stands. Falls are the major common injury related to hunting activity. http://surgery.osu.edu/trauma_burn/article.cfm?ID=6093
For tree stands, use safety harnesses. For constructed blinds and stands, make sure they are easy to climb and access safely. Consider how easily and safely the young and older hunters will be able to access them, while carrying gear in and out in the dark, with wet steps. This really is THE risk factor
5. Last, everyone reading this thread is far more likely to be seriously injured while driving to and from hunting than while hunting - the risk is orders of magnitude in difference. It is always amazing that people worry about things like this while eating a cheeseburger and fries and talking on cell phones while driving. If you want to do something to protect yourself, do not talk on a cell phone while driving. 1 in 4 car wrecks are now estimated to be caused by talking on a cell phone while driving. Hang up and pay attention.
From the National Safety Council.
Hands-free is Not Risk-free
With some state laws focusing on handheld bans and carmakers putting hands-free technology in vehicles, itís no wonder people are confused. However, while many drivers honestly believe they are making the safe choice by using a hands-free device, itís just not true. Your brain remains distracted by the conversation. Learn more about distracted driving.http://www.nsc.org/learn/NSC-Initiatives/Pages/distracted-driving.aspx?var=mnd
Last, if you are on a hunting lease, make sure to include that information on your annual homeowner's insurance policy renewal questionnaire. If something did happen, and a claim is made against you, the homeowner's insurance very well may provide coverage for you.