Keep in mind that for the purposes of Dwelling, it covers INSIDE your home / camper / (residence) only.
The definition of justified use of lethal force CHANGES depending on if you are inside, or outside of your home.
Inside your home you can claim justified use of lethal force if the entry is "tumultuous or violent", and you are preventing the commission of a felony. (Not forcible felony).
Outside your home - e.g. in your front yard, detached garage, etc - the definition changes to forcible felony. Which changes the rules significantly.
If someone kicks in the door to your house in the middle of the night, you don't have to meet "force with like force" - you can use lethal force to defend your home, period.
If someone breaks in to a detached garage, or shed, or your vehicle out on the driveway, now the definition changes as you are on "other property", you have to respond with force in like kind - you can't escalate to lethal force unless you are in serious risk of bodily injury or death (being threatened with a weapon, etc).
The same rules apply to a campsite; although you're technically prohibited from taking the loaded gun out of your camper / tent /etc anyway.
Our lethal force laws are somewhat confusing at first glance, but they get somewhat more clear the more you study them. The *safest* route to take under any circumstances is not to shoot unless you are in jeopardy of death or serious bodily injury; even in your home. If you do this, you'll meet BOTH requirements under the law, which significantly improves your odds of having the homicide ruled as justified.
Sec. 7 2. Use of force in defense of dwelling.
(a) A person is justified in the use of force against another when and to the extent that he reasonably believes that such conduct is necessary to prevent or terminate such other's unlawful entry into or attack upon a dwelling. However, he is justified in the use of force which is intended or likely to cause death or great bodily harm only if:
(1) The entry is made or attempted in a violent,*riotous, or tumultuous manner, and he reasonably believes that such force is necessary to prevent an assault upon, or offer of personal violence to, him or another then in the dwelling,
or
(2) He reasonably believes that such force is*necessary to prevent the commission of a felony in the dwelling.
Compare to other property:
*(720 ILCS 5/7 3) (from Ch. 38, par. 7 3)
Sec. 7 3. Use of force in defense of other property.
(a) A person is justified in the use of force against another when and to the extent that he reasonably believes that such conduct is necessary to prevent or terminate such other's trespass on or other tortious or criminal interference with either real property (other than a dwelling) or personal property, lawfully in his possession or in the possession of another who is a member of his immediate family or household or of a person whose property he has a legal duty to protect. However, he is justified in the use of force which is intended or likely to cause death or great bodily harm only if he reasonably believes that such force is necessary to prevent the commission of a forcible felony.
Note that in the first case, it's simply "felony", and the litmus-test for justified use of lethal force branches; in the second case, it is only "forcible felony", and there is only ONE claim.