In general, I've been switching so-called "critical hits" away from the common "20 on d20" to "5+ on the damage roll, mostly because I wanted special effects to be a little more common, but also to make it mesh with my general rule of rolling 5+ on 1d6 for something to change. Also, I hate the idea of "natural 20 is always a critical"; a so-called critical should be contingent on what a person is doing, not a guaranteed damage boost.
But there's already so-called criticals in the rules for certain monster attacks, like the purple worm's swallow attack. It's the same rule I included in the King Vulture I posted yesterday: target number +4 or a natural 20, if the attack is successful. This is a little more frequent than just a natural 20 for everyone (minimum 5% chance for successful attacks, but better odds for higher-level attackers.) And after the post on called parries, I thought: why not a called critical?
Any attacker with an appropriate weapon or tool that has a special extreme effect (such as severing limbs) can make a "called critical" attack to try to invoke it. If the attack roll is 4 or more points above the target number need to hit, or on a natural 20 for any successful attack, the extreme effect occurs.
Extreme effects need to be distinguished from simpler effects, like grappling, which only require a normal attack roll if they do no damage, or a 5+ on the damage roll, if they do damage in addition to the special effect.
An alternative critical mechanic is: on a successful attack, if the unmodified roll is greater than the target's Dexterity (or other ability score appropriate for the attack,) the called critical occurs. Again, a natural 20 for successful attacks is always a called critical.
If 20 is always a crit, then why would you not call a crit on every single attack?
ReplyDeleteWhat's the trade-off?
20 is not always a crit. It's a crit if your attack is successful.
DeleteAlso, three things:
(1) Maybe your weapon doesn't have a crit to call.
(2) Maybe the situation doesn't allow a crit.
(3) Maybe you don't want to do that, but something else, like subdue, or grapple and tie up.
Right now, I don't even have that many pre-defined extreme weapon effects. You'd only call a crit if you can think of one and I agree that it makes sense in the situation.
Talislanta had a mechanic sort of like this with something like Hit+ Intent for good hit rolls. I tried it for a time in my D&D game and it was fun until folks started getting lazy and I strike to blind or some such strike became dreadfully common. I think I fouled up by not limiting choices to properties of weapons used very much.
ReplyDeleteThe main -and in my opinion, most valid- objection to "natural 20 is a critical hit" I've heard is the relative frequency of criticals :
ReplyDelete-if a character hits with a 16, one succesful attack in five is a critical
-if a character hits with a 13 (better THAC0, to-hit bonus or whaterver) only one succesful attack in eight is a critical.
In other terms, a better swordsman will score relatively less criticals.