This is less a post and more asking for help. You have been warned.
As was pointed out to me by my most knowledgeable player (who may be more knowledgeable than me about GURPS, quite frankly), one of the things that could help immensely in convincing my group to make the switch from, "I hit it with my axe," to, "I take a Rapid Strike with the Flurry of Blows option to Feint once and then aim a swing at the leg with -4 for Deceptive Attack, which puts me at 14 because I have Weapon Master and Axe-Mace at 21," is to come up with a condensed list of tactical recommendations. However, y'all collectively have played a lot more GURPS than I have. So I need some advice from the community; I'm trying to boil things down.
Preferably, I'd have a class-by-class list of recommendations for different situations, along with explanations of why and wheretofore. For example, "As a Barbarian, you'll be relying on beats,"..."As a Scout, don't forget to aim for body locations, and try to take multiple shots,"..."As a Knight, remember Weapon Master makes you badass for reasons a,b,and c,"..."As a Wizard, stay out of combat," etc.
Before I start out, I should point out that +Douglas Cole has already done the groundwork for me, as well as some of the synthesis, and +Peter V. Dell'Orto has some reflections on making that useful to the GM.
(Who am I kidding? Is there a single one of you out there who didn't find out about this blog through one of those two? Still, it's polite, and I enjoy crafting links.)
The first principle, no matter who you are or what your profession, is this: you almost always want a skill of 14 when attacking. That's not at least 14; that's 14. Though even here there's a decision; maybe you want a 16?
Decide: is it more important for you to critically hit, or for you to hit? The rubric for this decision is simple: if you're unlikely to do damage with a simple hit (either because defenses or DR are too high), then you need a crit. Aim for skill 16. Otherwise, you don't; aim for skill 14. (There are a number of exceptions to this: for example, it's okay to go for skill 13 with multiple attacks, or even dip down to skill 12 if you're desperate, but the rule is pretty firm.)
From here, setting aside the people who shouldn't see combat at all, we naturally divide into two groups: melee and ranged.
Melee consists of Barbarians, Clerics, Druids, Holy Warriors, Knights, Martial artists, Swashbucklers (I won't be covering these two), and Thieves. Ranged consists of Clerics, Druids, Scouts, Thieves, and Wizards. (I'm only considering DF 1. Sorry, Innkeeper fans!)
For this post, I'm going to try covering Barbarians and Scouts. I'll be aiming this squarely at the templates as written, despite the fact that my PCs will have lower skill levels due to having lower point totals. Also, I'm totally ignoring grappling.
As a barbarian, your asset is your strength, not so much your skill. At best you will have Combat Reflexes and Weapon Bond along with skill 17 with some weapon. More likely, you'll have skill 16 or even 15. The basic threatening monster will have skill 14, which means defense of 10, +- any special abilities, like a high dodge or a shield.
In combat, Beats are your friend. (MA100) Especially important is that you can Beat without an extra action, if your attack was blocked or parried. If an enemy blocks, this means you (or the Knight!) will be more likely to hit him next round.
As a rule, try not to go below skill 14 with your main attack. Also, remember the Extra Effort options (especially Heroic Charge, which lets you move ant attack with less of a penalty, and Flurry of Blows, which lets you Rapid Strike better); you'll need them.
In combat, decide if your foe is high-skill or not. If he is, stick with Skill 16 and shots for the torso. If not, your go-to maneuver is a Deceptive Attack (-1), for -2 to hit (giving you skill 14 or 13). If he's tough to hit, consider a Telegraphic Attack (+4 to hit in exchange for +2 to defend). Don't worry so much about aiming at particular spots; you do enough raw damage that it doesn't matter that much.
Defensively, seriously consider taking the Defensive Attack option. For -1 damage per die (and you're doing a lot of damage already), you get +1 to Parry or Block, or the ability to parry with a U weapon.
With High Pain threshold you'll never suffer shock penalties, but you still don't want to get hit. Your defense is probably somewhere in the 11-13 area, which is decent, but not as good as a Knight's. Remember to retreat while defending, which gives you +1 to parries and blocks, and +3 to dodges (bringing your 10 to a 13, possibly your best score). Also, you don't want to get hit, because while you have a lot of HP you probably don't have a lot of armor. Don't forget your Luck or Extraordinary Luck, if you have it.
For berserker barbarians, embrace the beast! Remember you get +4 on rolls vs. knockout and death, meaning you'll practically never fail. (Only on an 18.) Your combat options are limited, though. You must attack the nearest foe, and you must All-Out attack. If your foes are highly skilled, take the +4 and trade it for Deceptive Attack against their defenses (usually for a total of -3). If they're not, go with Double, possibly also trading one for a Rapid Strike (with Flurry of Blows, costing 1FP) for -3 to your skill for three attacks, split how you like.
You're a ranged character. With skill 16 or 17 in melee, that might not seem true, but don't believe it - it's a lie. You're a ranged character. Those 20 points you sank into Heroic Archer prove it. Speaking of which, remember Heroic Archer and what it means. Here's the breakdown: no penalties for footing or positioning or actions, and if you don't move you've already aimed. So unless you can't avoid it, don't move. That takes your skill 18 and drives it up to skill 20, and you'll need that extra skill to overcome range penalties.
Unlike the combat monsters, you'll want to aim at body-parts or at chinks in armor; your base damage is too low to do much otherwise. Chinks in armor is tough at -8, but against large foes might be worth it.
The base effective skill you want is 14, because if you don't hit your foe doesn't even need to defend. Memorize the Size and Speed Range table from 2 yds to 20 yds, which is your maximum effective combat range. The further along this scale your target is, the fewer options you have. At 20 yards, just shoot once a turn for the torso.
While it depends on the exact nature of your opponent (high defenses? high DR? lots of people?) With high defenses, you'll want a lot of arrows on one target, to soak up defenses, or maybe a ranged deceptive attack, which is allowed. With high DR, you want to find weak spots and drill on them. With lots of foes, you'll want to send out a lot of arrows.
Also, remember: if you aren't being attacked, there's no reason not to claim the extra +1 from All-Out Attack (Determined).
One of your hallmarks is rapid fire. For a Fast Draw and two Bow rolls at -3 (or -1 if you have Weapon Master (Bow) or use 1FP) [*Note: Use of FP for this isn't RAW, but it has a nice symmetry with Flurry of Blows, so I allow it.] you can fire every turn. Do this every turn that the range is 7 yards or less. (Skill 18, +2 because you stood still, -6 is 14. 14 is your magic number.) If you use the FP or also have Weapon Master (Bow), aim for the vitals.
Speaking of aiming for the vitals, aiming for the vitals is your go-to maneuver. Expect to pretty much always soak that -3 to skill to aim for the vitals; the x3 damage multiplier is too nice not to. Other options are either not as good for you (arms and legs take less damage from impaling and piercing) or have better modifiers but are harder to hit (like the skull and eyes). In fact, a lot of the time you will be balancing aiming for the vitals with shooting every turn. Average damage through chainmail to the vitals is 3.5 x 3 = 10.5, or enough to take an average man down to a consciousness check in one turn.
What should you aim at? There are two schools of thought. The first is to aim at whatever's attacking the melee fighters; forcing it to use a defense against your attack makes their attacks more likely to get through. Another is to focus on whatever might be able to hurt them (or, say, the wizard) but that they can't hurt, like enemy archers. Which you subscribe to should depend on the situation.
If you're ever in a situation where you need to roll melee combat skills or defenses, leave. That is not your role. All-Out defend and get away.
You can think of that as a sort of first draft. The hope is that I'll be able to both pretty them up and add more to them, like what the Knight should do. Most will be simple, e.g. "As a Wizard, your main combat experience should be missile spells, and you want skill 14 with them if possible. Don't forget to All-Out Attack (Determined). If you're ever in combat, leave."
Is there anything I missed? Are my recommendations contrary to your experience? Do you have a better, clearer, more concise way of saying what I need to say? Please, let me know.