RPGMemes

I once let our monk deflect a ballista bolt because he said he was going to do the redirecting with his flying kick instead of his hands, so I had him roll acrobatics with disadvantage since his reaction time would have to be through the roof to pull it off.

rolled two nat 20's. Not only did that ballista go sailing right back at the machine that fired it, it utterly destroyed it and the three dudes manning it, because after kicking half a telephone pole back at your enemies, you've earned the right to walk away from an explosion without looking at it.

I also made him roll to see if he hurt himself landing and he did, so he had to deal with a bad ankle the rest of the encounter (-3 dex, I am a jealous god)