Critical Hits are explained on B381. They are a form of Critical Success when made with an attack roll.
Kromm on gun bursting
Use the attack roll to work out how many rounds hit, but roll only once -- for one bullet -- to find out the critical hit result. That's the 3e rule, and we're fools for having forgotten the extra sentence in 4e.
That round is a critical hit; no defense is possible, and it gets a roll on the table. All the others are normal hits, and the target may dodge.
- If "triple damage" is possible on a lucky shot, then in a set-up situation where luck doesn't come into it, it ought to be possible as well. So a strong man (but not a musclebound thug) with ST 11 starts at swing 1d+1, adds +1 for a sword, adds +1 for a fine blade, and adds +2 more for All-Out Attack (Strong). His damage roll is 1d+5, or 6-11. To the neck, that's 12-22. Triple it for ideal circumstances with all the time in the world, nobody fighting back, and endless practice -- let's say that a Professional Skill (Executioner) roll allows this -- for 36-66. Average is 51. That's -4xHP for most people, -3xHP for some really big ones. Three or four HT rolls are needed to survive. If the guy doesn't die (low damage, high HT), the rare second blow will mean an average of 102, which is automatically lethal even at 17 HP.
- Steal from the Forced Entry skill as well.
- Professional Skill (Execution): IQ/A
- This is the knowledge of how to kill another person quickly and cleanly in a controlled situation. It is of no use if you do not have complete control of your target and access to appropriate equipment (i.e., an executioner's sword as opposed to a normal combat-oriented sword, a chopping block, etc.) Add +1 per die to the damage done to the subject if you know this skill at IQ+1, or +2 per die if you know it at IQ+2 or better. Decapitation takes at least five minutes to set up (use standard rules for reducing or taking more time) and requires a roll against this skill as well as an attack roll against the subject's neck (almost always an All-Out Attack after Evaluating, net modifier +2). If both rolls are successful, the damage is tripled (for a net x6)!
Forced Entry (B196) normally applies to inanimate objects, and is the only way to get skill-based damage bonuses to weapons combat without being a Weapons Master.