Ever since the change to Deadliness , you can only start off the game with crit if you buy a Brawler's Glove first, or you use crit runes, or through a character skill like Ashe's passive. Normally on AD carries or AD top laners, you fill rune pages with 15 AD from marks and quints, and don't get any crit until you buy a Zeal. I've found great success in replacing 1-2 Greater Mark of Attack Damage with Greater Mark of Critical Chance. Without any crit, your crit is 0%, having something is statistically better than having nothing. One Greater Mark of Critical Chance will increase your crit to .93% - barely 1%. Though it's low, the occasional lucky crit in lane can really mess up your enemy laner thanks to the crit damage boost from Lethality . My reasoning for using a 2nd Greater Mark of Critical Chance is that it effectively doubles my crit chance of .93% to 1.86%. But consecutive runes will not double my crit chance, so I stop at 2.