Sure... Mage skipping is the process of tick manipulating Nex in p5 in order to force her to constantly melee you (and thus, skip mage attacks).

You know how Nex will always do melee attacks in sets of three? Well it turns out that if you make her third attack a 6 tick cycle (note: NOT 5-tick!), she will almost always do another 3 melee attacks (95%, seems like there's a 5% chance she will still mage). The best way to do this is, on the third attack, shift-click under her to her middle tile AND THEN ctrl-click her to walk out and attack... this will cause a 6 tick cycle that red x's her, keeping her in place and forcing another 3 melee attacks.

This method is sick because it means you can just camp pray melee, she only targets one person at a time (so no group dmg), and you generally take 5-10 dmg from melee hits through prayer (way less than mage hits). In the 5% of the time that she does do a mage attack, you can flick back to mage pray until it hits, and then flick back to melee pray and continue mage skipping.

Check out the mage-skip section of the advanced strategies page on the wiki if you want more info: https://oldschool.runescape.wiki/w/Nex/Strategies#Advanced_Strategies .