HOW TO PREVENT CHEATING AT CHESS TOURNAMENTS?

Say for instance, the opponent walks in with a pen filled with INVISIBLE INK, (i.e ink that disappears after an hour)

and switches one's own pen for said invisible ink pen,

and distracts the opponents attention for a moment

and rearranged the board into the 4 move mate?

If it's anything below GM level chess, there would be no real measures in place and

A sizeable prize fund could be thus walked off with.

(If the opponent shows the scoresheet as proof to the arbiter, uh oh, the invisible ink has dried)

What to do if something like this happens?

Invisible ink pens allow you to write things down that aren't immediately visible. (You have to use a reagent to make the letters visible.)

Anyone given a pen that didn't appear to create visible letters would be likely to immediately replace it.

People have come up with the nuttiest ideas about cheating in chess from anal beads to invisible ink. Just about anything is possible when your imagination runs wild but in ordinary non-professional tournaments in which I played in the 80's and early 90's before the internet and computers about the only cheating that took place was taking advantage of new players and their ignorance of the rules. As a newbie in a tournament in Alabama one time my opponent ran out of time but somehow he convinced me otherwise even after I called a monitor. I didn't know how to claim a win and the game went on and I lost. Online I can see anybody cheating since there is no monitor in a private home. But over the board and in person most cheating would be obvious as long as the rules of no cell phones or smart watches are enforced. It would be very difficult to cheat in professional tournaments OTB.