Stab vs Slash: When to use both

Summary: With bladed weapons: slashing is good for causing tissue damage, stabbing is good for killing.

In Kali / Escrima / Arnis one of the primary attacks taught is the slash. I read once that the ancient Romans found it amusing that their opponents did so much slashing because the stab was so much more efficient at killing. The Romans themselves did a lot of stabbing and this can be somewhat evidenced by the short length of their swords.

This is a pretty readily apparent notion, so why do people slash?

More damaging in some areas

It's generally not a good idea to slash the body. Stab just about anywhere on the torso (major organs, etc) or parts of the arms and legs close to the torso (major blood vessels) and you'll likely have a killer blow. Don't waste a shot slashing.

However, the same is not true for the outer arms and legs. A stab can penetrate these and not cause death because there are no vital parts of the body there. What you want in these areas is as much tissue damage as you can get.
A stab can be less damaging than a slash to these areas. A slash can cover a greater area and on an arm or leg this can mean more tissue damage. Cutting through skin, muscle, tendons and ligaments is the goal. With larger weapons of the past the goal may have been to break bones or completely sever a limb.

Wider attack

Also, the slash is a bigger attack than the stab. It requires much less accuracy and can do damage over a wider area. This is perfect for limbs which are smaller and also moving around much less predictably (swinging weapons and shields) than a torso.

Slashing's large range also makes it a good shield even while in motion. A weapon with its tip pointed at your opponent protects much less area than one held upright.

Disabling

Kali teaches striking the closest target with your longest weapon. Example: hit his extended hand using your sword. This is good fighting strategy.

Disable your opponents weapons and you will have a much easier shot at your killer blow.

Non-bladed or hacking weapons

Force is key with non-swords: sticks, staves, axes, maces, flails. In most cases it makes much more sense to use a slashing motion with these weapons since your goal is not penetrating the torso to hit vital parts of the body. You want impact, not penetration.

This is significant to Kali training since the art teaches "One technique, many weapons".

Caveats

Historically things were very different in different times and places. Different types of armor, weapons and shields greatly affected fighting styles. So did the mechanics of field battle - you don't spar with anyone out in the field like you might one-on-one, you go for the kill as soon as possible. Field technique is much more committed and fast-paced. The number of attacks you get per person is limited because of formations (advanced armies), position strategy (you need your flank to get somewhere fast to make the attack successful), the possibility of multiple attackers and because you're holding up the line of fighters behind you.

Photo credit: hans s