New House Rule: Roll a 12-Sided Die to Bring Balance to Critical Hits
The critical-hits system currently in use by the official rules of Dungeons and Dragons 4th edition calls for an attacker to obtain a natural 20 on his or her attack die (page 225 PHB) and the roll must also qualify to hit a target’s defense without relying on an automatic hit to hit. So long as these two criteria are met, a critical hit is obtained. This is not a balanced system, though, and here’s why: a poorly skilled fighter, though he doesn’t hit as often as a highly skilled fighter, will, when he does hit, experience a greater percentage of his hits as critical hits. For instance, if the fighter needs a 19 or 20 to hit, the fighter will experience a critical hit with 50% of all hits. Meanwhile, a more skilled fighter who can hit on a 10 or higher will experience a critical hit with one out of ten hits (10% of all hits).
To fix this problem, I propose rolling two dice when attacking instead of one—a 20-sided die and a 12-sided die—and they should both be rolled at the same time.