Trial and error of course!

John didn't even know where to start. The gun fired and things changes. He understood as such, but how did it actually work? Could he influence how the gun affected things?
Just like a boon from the heavens, a very helpful clue presented itself to him when James eventually got up from his chair. Falling out of his left rear pocket was a folded flyer of sorts. Upon further inspection it appeared to be a crudely made flyer for some brothel or hooker service. Thinking back to the moment where he pulled the trigger, John remembered the light being focused around that area for a split second before it pulsated outwards to cover the rest of the scene. Had it really latched on to that flyer?

It wasn't nearly enough to go off of. James even refuted to ever having picked up such a flyer at any time, though he certainly would've if someone had offered it to him..
Little did they know that the flyer had been planted on him earlier in the day, during his date with the now turned hooker. Some random whore had been walking around town all day handing out flyers, even going as far as folding them up and sneaking them into the pockets and bags of random passersby.

With the first piece of the puzzle uncovered, John turned to the gun itself. Perhaps there were some hints to be found there?
At a glance it'd just seemed like any prop gun you could buy from a vendor or store. Some random details here and there, a fake serial number and other carvings whose only purpose was to make the gun seem more authentic. It wasn't until he brushed his thumb across the handle of the gun when John noticed something out of the ordinary. The gun seemed to be reacting to his touch, with glowing letters coming into view as he rubbed it. After carefully reading them out one by one in succession he though it said "hekhov's gun". Being the Zoomer that he was, John's first instinct was to google Hekhov's gun. Thankfully it was autocorrected to the actual inscription which was supposed to read "Chekov's gun" had he bothered to rub a tad further down on the handle..

Sure enough, the very first hit he got was a pretty comprehensive explanation of Chekhov's gun. Being the university student that he was, albeit not the brightest of the bunch, he managed to made sense of what the gun was capable of to some degree.
He deduced that the gun made the planted flyer much more relevant to the scene than it otherwise would've been. Hadn't it been for the gun intervening it probably would've been ruined in the washing machine and confused the ever living hell out of James who apparently had no idea the flyer was ever in his possession.

Understanding the theory behind the gun was simple enough, the true art was wielding it in a way that allowed him to control the outcome. The change to James and what he assumed to be his next fling was anything but controlled. There's only one real way to learn how to use something, and that's by using it! No time like the present he thought as he turned around in his tracks, once again reaching for the front door. There may or may not be an assignment with a ominously near due-date, but John had been looking for any excuse to procrastinate as he usually did with these things.

University campus was what John liked to refer to as a "target-rich environment", though usually meant in a different context entirely.. God knows why he felt that way, considering his complete lack of "rizz". Speaking of rizz, here came one who famously had plenty. Enter the stereotypical Chad. With a distinct jawline, perfect hair and way above average physique it was almost comical how his real name was Chad. The only descriptor lacking from his repertoire was that of being a quarterback or generally just being a sport-jock. No, Chad preferred to do his exercise in the gym like a sane person, avoiding traumatic brain injuries from repeatedly having ones head bashed in by linebackers. Safe to say that Chad wasn't just one to care for his looks and health, his goals in Uni were strictly academic, though he definitely enjoyed the social side of things as well. Curiously enough, John didn't possess the same feelings towards Chad as he had James. Probably because they weren't roommates, but the fact that Chad carried himself more humbly than the counterpart was probably mostly at fault. He looked good and he knew it, but he didn't let it get to his head. He was probably more grounded than most of the students there anyways.

John assumed that Chad was on his way to a bar or social meeting of sorts based on the way he was dressed. He wore tight fitting jeans, sneakers and a nice, black shirt that had a few too many buttons unbuttoned. Now to decide what to aim for.. John assumed that the target in question had to be in the vicinity of an object or "detail". Perhaps it'd be best to go with something simple, "damage limitation or something" John thought to himself..

What about a light pole? That wouldn't lead to a weird scene, surely..

Ready, aim, fire!

Just like before, a beam of light shot out from the tip of the gun and struck it's target true.
Thanks to the light pole being much larger than the flyer it was much more prominent when it too was enveloped in light. Though Chad was a good few steps away from said pole, John's intent on making it the object or detail in question swayed the gun enough to consider it as such.

At the moment of firing John didn't think of anything in particular but the light pole and Chad. With no strong emotions in his heart, the gun was free to act. So what significance would the seemingly insignificant pole have on Chad's scene as he made his way towards a good night out? What better way to use a pole than for ..climbing?!

With seemingly no goal other than to climb it, Chad leapt up the base of it and continued ascending until he reached it's "peak", at which time his goal seemed to be achieved and he with much less pace made his way back down before continuing on his merry way.

Meanwhile John tried to keep his muffled laughter from escaping his tightly sealed lips. What did he just witness? Hadn't he known it was the effects of the gun at play he would've chalked it up to being a psychotic break or something. There were definitely some fun to be had with this thing!

So to summarize. John reasoned the gun was capable of establishing symbolic meaning, like it did with the flyer. Or was that a bit of a stretch? Could it be considered symbolic if the item was planted on the person in question? Was it more thematic perhaps? If the flyer set the "theme" for the scene, would it also be capable of having random objects have a symbolic significance if he willed it? To conclude, John still knew very little about the capabilities of the gun. One thing was however absolutely certain, it had the potential to be A LOT of fun..