The is (was?) a whole thread about this over on the SJG Forums. I saw the title, and emailed Doug and said, "That's our next Melee Academy." But I haven't read the thread itself. I wanted to basically put forward the tactics I've seen work in play when forced to fight unarmed versus a foe with a close combat-capable weapon and the intent to use it.
Unfortunately for this post, I also got a sudden, huge, last-minute influx of good paying work, which killed the free time I'd budgeted for a page reference and turn-by-turn tactical description. But this still might help, so I'm posting what I have.
These assume Basic Set and Martial Arts rules. If you use Technical Grappling, some of these options will work very, very differently. Lucky for you, Doug has you covered over at Gaming Ballistic.
The basic tactic for unarmed vs. knife is pretty much:
- Don't get hit.
- Defend if you do get hit.
- Grapple the weapon arm. Per B371, this makes it impossible to strike with the weapon in it.
- Arm Lock (if you can) or strike (if you can't). Don't let go of the arm.
Don't Get Hit
Goal number one, avoid getting hit in the first place. There isn't a lot you can do to ensure this, but if your skill is better you can try this one:
If your skill is much, much better (think, 10+ skill points) than your opponent, consider this option. Use Defensive Feint to lower the chances of being hit. Hopefully, this forces your opponent into a normal, non-Deceptive Attack, or possibly even a Telegraphic Attack. Then you can use your effectively improved defenses.
Otherwise, All-Out Defense is your friend while you just pray the guy rolls an 18 on his attack.
All-Out Defense is probably the best option to start with. The unarmed fighter will want to All-Out Defend (Increased Defenses) for a +2 to Parry if intending to use the Parry to set up an Arm Lock. +2 to Dodge is also good if you have a superior Dodge and intend to set up your own grapple later. Double defenses (use Dodge first) is also a good option.
Retreat is tough, because you want to avoid getting hit but you don't want to stray any further from the foe than you can. A weapon gives him a reach advantage (in Tactical Combat) so you will want to stay close so you can attack when your turn comes around.
Eventually, though, you'll need to stop using AOD and start attacking.
Grapple the Arm
There is a -1 penalty to eat up when you grapple the arm (and -2 for hand), but you need to - just like in real life, in game, you'll want to immobilize the weapon.
Feint, then Attack
If you think you've got superior skill to your opponent, use Feint to lower his defenses. Use Beat if you think your ST+skill and you successfully used Parry to defend against his weapon.
In any case, when you attack, use Deceptive Attack aggressively. As in, drop your skill all the way down to 10. You can afford to miss but can't afford to be parried since that will result in a free chance to cut you. Once you've got it, look at Arm Lock or using strikes (I like Knee Strike here) to disable your opponent or remove the weapon. You no longer need to worry about being weapon parried, because you've got the arm.
Ultimately, though, none of these are optimal - it's a case of "X-1 vs. X" and, surprise surprise, you're better off being the X not the X-1 in that equation.
That's the basic cycle I use. Avoid getting hit, Feint is you think you have the skill edge, use Deceptive Attack aggressively to ensure you only hit when you've stomped his defenses down, and hold to the arm and do violent things to your opponent.