FEND: Fully Enabled Defenses (GURPS 4e/3e)

Defense stats in GURPS are based on skill divided by two, an odd mechanic not used elsewhere in the game. What if defense used full skill, just like any other skill-based action?

This GURPS rules hack is a look at a simple, single, “for the heck of it” rules change, followed by the usual commentary. As always, it’s yours to use, abuse, or refuse, as you choose.


v1.0: Created 2003/04/28

v1.1 update (2009/07/27): Modified for use with 3e or 4e.

Using Full Skill for Defenses 

There’s one funny bit in the GURPS skill system. Nothing that need ever actually bother anybody, just a little oddity that’s so basic to the system we never even think about it.

To test any skill, you roll against skill level, with bonuses or penalties to change the probability of success.

With one exception. Defenses are rolled against half (or sometimes in 3e, two-thirds) skill level. Harmless, true, yet it’s an oddball mechanic that’s used nowhere else in the game.

What if defenses used full skill level, like any other skill? Yes, that suggests shockingly high defense rolls, but appropriate penalties would help keep things in line. Here’s how it might work:

Active Defense rolls

Just as “to hit” is abbreviated “TH”, we’ll abbreviate “to defend” as “TD”. A TD roll is an active defense roll (Dodge, Parry, or Block).

The good news for defenders

1) Active defenses use full skill level. There’s no “skill/2” or “two-thirds skill” or so on.

2) For Dodge, use Basic Speed x 2, i.e., (DX + HT)/2. Round down.

3) Under 3e, skills with an improved Parry, like Fencing, Brawling, or Judo, should continue to benefit in some way. A bonus of +1/8 skill (round down) works acceptably.

Example: Jim has Basic Speed 5.75, Broadsword-12, Brawling-16, and Shield-14. His defense rolls (so far) are Dodge 11, Broadsword Parry 12, Brawling Parry 16 (or 18 using 3e), and Shield 14.

The bad news for defenders

Full skill doesn’t mean parrying a weapon is easy! Swinging your sword to hit a six-foot target is one thing; positioning it to deflect a little knife is another.

Just as attacking a foe’s weapon takes TH penalties for the target’s small size (BS 110), so attempting to parry or block a weapon takes TD (“to defend”) penalties. The rules:

1) Using 4e, don’t add the base +3 to active defenses. Using 3e, don’t add PD from armor; drop it from the game entirely, as discussed a bit here.

2) Take a -4 on Parry or Block vs an attack, as you’re essentially trying to “hit” a small, incoming target. It’s not easy!

3) Take a -4 on Dodge too. (That’s not a penalty for weapon size – you’re looking to avoid the weapon, not “hit” and deflect it. It’s a penalty for the inherent difficulty of dodging, moving your whole body instead of an arm.)

4) Under 4e or 3e, you can handle shields normally, letting them add a DB or PD bonus to defenses. But see rules for Shields and Cover and Shields and Size for tweaks you might want to implement. In particular, under 3e where shield PD is high, you might allow its bonus only on a Block.

Example: The above adjustments lower Jim’s TD rolls. His Dodge is 7. His Broadsword Parry is 8. His Brawling Parry is 12 (or 14 using 3e).

Remember that under 3e and FEND, none of these defenses get a PD bonus from Jim’s scale armor!

Playing it

Attacks and defenses

Roll TH and TD normally.

Example: Jim needs to defend against a sword blow. He can choose from defenses including Dodge 7 or Broadsword Parry 8.

Defense modifiers

As FEND boosts defense scores, it will make sense in many cases to double TD modifiers. For example, crawling carries a -3 TD penalty; double that to -6. Double the Dodge penalties for encumbrance as well.

However, don’t double bonuses, such as that from Retreat. They’re fine as they are.

Example: If Jim needs to parry a swung sword bare-handed in an emergency, he can use his Brawling skill’s Parry 12. But there’s a -3 penalty to do so; double that to a -6. Jim is left with Parry 6, and risks arm injury if he fails.

If you find some instance in which a doubled TD penalty plays poorly, don’t double it. Use your judgment.


Feints work just as they do now, but with double the TD penalty. For every point of the feinter’s success in the Contest, reduce the defender’s next defense roll by 2.

Example: A foe Feints vs Jim’s Shield skill of 14, and wins the contest by 2. If the foe attacks again immediately, Jim will defend at -4.

Deceptive Attacks

The Deceptive Attack maneuver, foreshadowed here and now a part of 4e, is important under FEND as it provides a means for skilled fighters to overcome foes’ high defenses. Use it freely with double the TD penalty:

For every -1 TH taken by the attacker, the defender takes -1 TD.

Defense and size of defending weapon

It’s hard to catch an incoming blow on a small weapon. Double GURPS‘ Parry penalty for using a knife or other small object to -2. (Or feel free to leave it at -1 for a large knife, or anything between a regular knife and a short sword in size.)

Conversely, it should be easier to catch a blow using a large item – and it is. That’s why shields add a DB or PD value.

Unarmed combat

There’s no reason for an attack to follow a separate set of rules when it’s a grapple. Instead of a Contest of DX, why not play a grapple as a normal attack, like this:

1) Roll vs straight DX, Judo, Wrestling, or Sumo Wrestling to hit.

2) If TH succeeds, the defender rolls a Parry, Block, or Dodge normally (based on full skill -4, as above).

Normal TH modifiers (for target size, etc.) and normal defense modifers apply as appropriate. Feints, Deceptive Attacks, and other normal combat rules may be used.

Two-handed grapple: Under 3e, the above TH roll is for a one-handed grapple. For two hands, apply the +3 TH that GURPS suggests.

Or use this alternative: Give the attacker +2 to hit, and the defender -2 to defend (as there are two “weapons” coming in simultaneously from different directions). I don’t know why, but I like this method.

(4e seems to have lost this distinction between grappling with one hand vs two. If you want to bring it back, use the above.)

Comparing things to GURPS

High defenses?

Why did GURPS employ the unusual “skill/2” mechanism for defenses to begin with? Presumably because defenses rolled against full skill playtested poorly. After all, even with skill halved for defenses, gamers complain of too-high “unbeatable” defenses in GURPS, especially before 4e.

And yet, FEND then goes and bases scores on full skill! Lunacy!

It’s true, FEND does raise defense rolls for most skills at a skill level over 14. At the same time, it offers means of keeping TD in check, beginning with the blanket -4 TD on defenses and no use of the flat +3 bonus, plus the doubling of penalties to defense.

Using 3e

The suggested 3e bonus for Fencing, Karate and similar skills with improved Parry is kept modest in FEND. Most importantly, FEND only lets armor boost defense rolls in one limited case (a shield’s PD value adds to Block); armor otherwise does not aid TD. That alone removes a big cause of “unbeatable defenses” in 3e. Don’t be surprised to see FEND result in lower defense rolls for many heavily armored characters!

See Other Notes below for further suggestions related to Retreat bonuses and encumbrance penalties that can help hold down defense rolls.

FEND tactics

Tactics become all the more important with FEND, whose rules multiply the defense-penetrating effects of Feints and Deceptive Attacks.

Even when facing down lesser foes too unskilled to deploy those measures, a cocky Broadsword-20 fighter will find his Parry 16 made worthless by rear attacks, massed attacks, missiles, disarms, tackles, and other common-sense tactics.

Remember that any TD penalty you can inflict upon a foe is generally doubled in FEND. Put on your tactical cap and do your worst.

FEND game feel

FEND increases the defense gap between skilled and unskilled fighters; the difference in TD becomes the same as the difference in TH. That’s good for a heroic feel, in which PCs mow down mobs of scrubs while taking little or no injury. In particular, gamers who unleash feints and Deceptive Attacks on cannon fodder foes should enjoy faster, more decisive victories.

Of course, the same works in reverse. Barring GM pity and fiat, the novice swordsman PC who takes on the blademaster will go down more quickly than ever under FEND. See the notes on tactics above, and choose fights wisely.

Overall, FEND should contribute to a cinematic feel in games with cinematic skill levels. In realistic games that enforce more modest skill levels, FEND produces modest effects not much different from the current game.

Either way, FEND’s effects should be most welcome to players of GURPS 3e, under which defense scores could easily be uselessly low or “unbeatably” high. FEND may seem less necessary under 4e, which takes steps to avoid those extremes of defense scores (and also gives attackers the needed tools to defeat high defense scores). In fact, FEND will reduce defense scores for low-skilled fighters in 4e, an effect you may or may not like. Give it a try and see. 

Other Notes


Below are suggestions for the effect of encumbrance on athletic combat skills. (“Athletic” here refers to any skill using full-body movements, whether Karate, Knife, or Polearm, but not skills like Bow or Guns.)

Dodge: Using FEND, encumbrance levels have twice their normal effect on Dodge, e.g., Light encumbrance offers -2, Medium -4, etc.

Martial arts in 3e: GURPS 3e applies a binary “Light encumbrance or better” restriction on some combat skills. GULLIVER suggests a better way, as 4e now does: Use encumbrance level as a skill penalty on these, for all purposes. You can use Karate with Heavy encumbrance, but your skill of 17 becomes a 14, for attack, defense, feinting, damage bonus, or any purpose.

Other combat skills: GURPS applies no encumbrance penalties to other combat skills. As an option, though, apply half encumbrance level as a penalty to other athletic skills (i.e., most combat skills), for all purposes. That’s a marked rules change, but it’s realistic, and provides another small aid in keeping FEND defense rolls reasonable.

Summary: Using FEND, apply twice your encumbrance level as a Dodge penalty. Apply your encumbrance level as a skill penalty to martial arts with encumbrance restrictions (this is a more flexible replacement for the GURPS 3e rule). As an option, apply half your encumbrance level as a skill penalty to all other athletic combat skills.

Options for Dodge

The Dodge calculation remains a GURPS oddity of a statistic that averages two attributes. But that should upset no one; other RPGs use this sort of figured stat all the time.

You are welcome to substitute this with some other calculation of Dodge, but beware of using straight DX – most gamers already find a problem with this one attribute offering too much power, especially in 3e.

Options for Retreat

The Retreat bonus should be left as is under FEND. But in addition, FEND for 3e suggested an optional way of further reducing the Retreat bonus to keep defenses in check (which now happens to be the official 4e method): Use the +3 bonus only for a Dodge, and allow only a +1 for a Parry or a Block. 

For either 4e or 3e, there’s one more tweak you could make to limit the Retreat bonus:

To get the full +3 bonus (a Dodge in 3e or 4e, or also a Parry with some skills in 4e), your Retreat must carry you out of the weapon’s Reach; otherwise, the bonus reverts to only +1. This boosts the danger of foes with long weapons! 

(A final option to put on top of that: If your Retreat doesn’t take you out of Reach but takes you to a side rear hex, instead of to the rear hex, you can get a +2 bonus instead of the full +3. If you can’t jump out of a long attack’s Reach, you can at least try to sidestep it.) 

Defenses and size of the attacking weapon

The -4 penalty to Parry or Block a weapon should technically vary with weapon size, just as GURPS suggests a -3 TH vs a long (two-hex) weapon and -5 TH vs a small (Close) weapon like a knife. An unarmed attack would also be -5 to Parry or Block.

The FEND rules stick with a flat -4 TD for simplicity. Switch to varied modifiers if you want the detail.

Other ways to keep defenses in line

Do you like FEND, but still want a little more aid in taming those high defense rolls? Take a look at the shield-related articles linked to earlier for more ideas, and check out DECIDE as well. 

The wrap

FEND is pretty experimental, and can no doubt use more tweaks (especially for 4e). What do you think?


  • Diomedes

    Rapid Strike

    The Rapid Strike maneuver, foreshadowed here and now a part of 4e,

    You should probably make a note that Rapid Strike, while a part of 4e, is called Deceptive Attack, and 4e’s Rapid Strike is something else entirely. That confused me when I first read the passage.

    • tbone

      “Deceptive Attack” is of course what I wanted to say, but somewhere “Rapid Strike” jumped into mind, and for the half hour or so I spent editing, I just kept writing that again and again…

      It’s fixed now. Thanks!

  • crispythemighty

    As a person who is trying to get their gaming community into GURPS I like this. It simple for one and it works for two. Sure there is a small deal with remembering to double penalties but removing the half skill + 3 mechanic and replacing it will skill – 4 is easier to explain to players.


    Side Note: It has been awhile since I’ve checked your blog. I like the new setup.

    • tbone

      I agree, it’s easier – and I like that the “-4” isn’t just an arbitrary mod, but is a reasonable penalty for the difficulty of blocking a small(ish) weapon, the same as the penalty to hit such a weapon.

      Still, it calls for lots of testing, by lots of players, to see how unbalancing it makes things – especially, its further stretching the effectiveness gap between high and low combat skills. Under FEND and 4e, low-skill fighters will want to use lots of Dodge + Retreat actions.

      Glad someone likes the site design. It was actually a really hasty swapping of graphic theme, out of pique over some quirks of the last one. But it seems a good one.

  • Douglas Cole

    Seems to me that you have a nice 4e setup here for FEND, where “Parry” and “Block” are Techniques (capital T) that carry (in your system) a built-in penalty of -4. This would indicate that they could potentially be improvable from the base. It would definitely be a HARD Technique, and it should certainly be capped, either at skill or even below skill.

    Down side of FEND is that the percent chance of defending goes up VERY quickly with skill, as you’re walking up the bell curve twice as quickly as with the 3+Skill/2 method.

    At FEND of Skill-10 (normal 4e Parry 8), you’re at a 6. At FEND Skill 18, you’re at 14 vs standard 4e defense of 12. Your way is identical only for Skill 14 (which is fine); above this skill and defenses get better quickly; below and they fall off.

    Surivial at skill levels of less than 14 will suggest fighters spend a few character points on Parry early on; it’s one of the best ways (if it’s a Technique) to stay alive early in game.

    • tbone

      I agree, Parry (or Block) could be made techniques under FEND. It’d be as simple to implement as any other existing technique. But there’d be two downsides:

      1) The problem of very high defenses, as you note. There should definitely be a cap, such as Skill -2 – but wherever the cap is set, the result is still a BIG defense bonus for a very minor point cost.

      2) Parry/Block is arguably a “core” ability of a melee skill, on par with attacking. Thus, if attacking remains disallowed as a technique under FEND, Parry/Block should remain disallowed under it as well.

      Douglas Cole wrote:
      Down side of FEND is that the percent chance of defending goes up VERY quickly with skill, as you’re walking up the bell curve twice as quickly as with the 3+Skill/2 method.

      Right. As for whether or not that’s bad, I’ll only note that ALL other uses of skills in the game follow precisely that connection between skill level and chance of success. It’s somewhat too bad that defenses, and defenses alone, need to follow a separate scheme!

      Incidentally, I wouldn’t be at all surprised if Steve Jackson himself started his GURPS/Man-To-Man designing (almost 30 years ago now?) with defenses rolled vs skill, as with any other use of skill. Assuming so, it’d be interesting to find out whether he tried or at least considered a FEND-like penalty too, to rein in what’s clearly otherwise too high a chance of successfully defending.

      Likewise, I wouldn’t be surprised to hear that he did try something like FEND, and rejected it (probably wisely so!) in favor of the Skill/2 method, for overall better game play. But I’m just musing. And whatever the official design reasons for Skill/2, it’s fun to try out FEND as an alternative.

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