Hypothetically speaking, let's say four pirate hetero lifebros are wandering around inside the imaginary landscape of a deity's brain hole and they encounter a dragon of all things. The dragon has like a really really good send of smell, and the lifebros can hear the thing coming so nobody is surprised when the pirate bros see the giant lizard burst from the trees into a clearing about ten yards away from them and it in turn sees them.
The four bros have been wandering around in this weird ass place for some time now, so they've all got weapons out and their various special effects popping. The dragon has a basic speed of 8, the Elduman has a 5.25, the Sereth has a 6.25, the sorcerer has a 5.5, and the actual pirate has a 6. So, the dragon goes first, following by the Sereth, the sorcerer, then the Elduman, and finally the actual pirate.
The dragon doesn't know what guns or Elduman or sorcerers are, but it's been around a while and has seen a sword. it doesn't like them. It uses a move maneuver and moves 8 yards towards the pirate. Noticing it is still 2 yards away from dining on man flesh, it uses a move and attack maneuver and moves the last two yards to the actual pirate and bites him. The dragon's Brawling skill is 9 (it's actually 16, but move and attack confers a -4 penalty and the skill level can't exceed 9), and it rolls a 9, so it hits. The actual pirate, being aware of his opponent is like fuck! and tries to twist out of the way. He rolls against his dodge, which is 11 (9 plus one from Enhanced Block: Dodge plus one from his magic ring), and gets a 10, dodging out of the way. The dragon, is peeved by this and attacks with a claw, rolling a 13 against it's Brawling skill of 16. Another hit. Karrak gets a 9 and manages to dodge out of the way.
The Sereth, lingering about two yards behind the group, decides to take an aim maneuver with his beloved rifle and takes a step back, now being about three yards away from the dragon. His next attack with the rifle will be based off of an effective skills of 24.
It's the actual pirate's turn, and he has this massive forty foot dragon breathing rotten, caustic breath into his face. Shit. He takes a move and attack maneuver and swings his black short sword into the dragon's snout. He rolls a 10 against his Melee Weapon (Shortsword) skill of 19.(-2 for moving and attacking, +1 for the sword's enchantment, +5 for the dragon's SM), which is a hit. The dragon, being a dragon, doesn't block or parry, it simply jerks its face out of the way of the blade and rolls a 16 against its dodge of 11. That's a fail on the dragon's part. The actual pirate's ST is 10 so his thrust damage is 1d-2 and his swing damage is 1d. The enchantment on the sword improves these to 1d-1 impaling and 1d+1 cutting. The sword itself is responsible for the impaling and cutting stuff, not the enchantment. The actual pirate's swing does 7 cutting damage. The dragon has thick ass greenish brown scales, and a DR of 21 chews up that damage and spits it out. The dragon has no idea why the actual pirate swatted it on the nose with a rolled up newspaper.
The sorcerer, being sorcerous, begins casting a spell. He concentrates and moves away from the dragon (now being about 3 yards from the big lizard). The ambient sorcerous energy of this deity's brain hole appears to be similar to The Known World and the sorcerer has ten energy at his fingertips and his Magery allows him to pour 2 energy into his spell. A smoking ball of incandescent fire glows from within the barrel of the sorcerer's firearm and he rolls an 11 against his skill of 15 with the fireball spell.
The Elduman takes a concentrate maneuver and steps away from the dragon as it thrashes and bites at the actual pirate. The Elduman is now one yard from the dragon. The Elduman normally has a psionic Energy Reserve of 10, but he activated his Elduman Resilience about 30 seconds ago, so he's down to 9. He burns another 3, bringing him down to 6 and slams psychic crush into the dragon's brain hole. He rolls a 9 against his Will of 9 and "hits" with his psionic power. His Will is actually 10, but psychic crush takes a to hit penalty of -1 per yard from the target you are, just like spells. The dragon attempts to resist this psychic intrusion, and rolls a 10 against his Will of 10 and glares at the Elduman. Since psychic crush is a malediction, the hit/resist stuff is actually a quick contest. To affect the target, the Elduman needs to win the quick contest, so since it's a tie, the dragon successfully resists.
The actual pirate steps back one yard after his ineffective swing and branishes his pistol. Taking an attack maneuver, he rolls against his effective Guns skill of 21. A hit. The dragon rolls a 12 against an 11 on his dodge. The bullet cracks into its scales, 11 damage from the 2d+1 firearm. Doing nothing. The actual pirate drinks heavily as a free action.
At the end of this first second of combat, everyone is still at max hit points. The Elduman is down to 6 points of energy in his energy reserve (but he still has energy in his ring and regular FP to spend) and is one yard from the dragon, the sorcerer is casting his spell about three yards from the dragon and has two energy in it so far. The Sereth is hanging back and getting a seemingly unnecessary bead on the forty foot long lizard.
The dragon spits acid at the Elduman and rolls a 6 against his Innate Attack skill of 16. The Elduman tries to dodge and rolls an 11 against his dodge of 9 and takes 13 points of corrosion damage. His Elduman Resilience is up and running, so that slides down to 7 corrosion damage. His clothing has a DR of 1, so that's down to 6 damage. Because it's corrosion damage, the Elduman's clothing is pretty much ruined and won't protect him anymore. The Elduman takes 6 damage, reducing him to 4 HP. He's just taken a major wound (one that did more than half his HP in damage) and he rolls an 11 against his HT of 10. This is a failure and the Elduman falls to the ground, stunned. He can defend himself at -4, but he can't take any actions on round 2 and will make a HT roll at the end of his turn to recover. This continues till he recovers.
The dragon turns its attention back to the actual pirate, now quite pleased with itself. It lunges towards the actual pirate and makes an attack maneuver with its teeth, rolling a 13 against its Brawling of 16, a success. The actual pirate rolls a 14 against his dodge of 11. The dragon rolls 3d and does 15 cutting damage to the pirate. Our actual pirate calls on his Gifts (paying one FP to do so, reducing him to 14) and rolls an 11 against the 11 needed to activate Buffered by the Sky. The 15 cutting damage is reduced by 4 to 11 and then hits his pirate outfit, which I'm assuming is roughly equivalent to leather armor and has a DR of 2, dropping us to 9 hit points of damage. It's cutting damage and the actual pirate has no Injury Tolerance or anything so it gets multiplied by 1.5 to 13 damage and drops him to 0 hit points. He rolls a 4 against his HT of 12 so he isn't dazed or knocked down. Every time you take damage in GURPS, there is something called a shock penalty equal to the damage you take, capping at -4. So the actual pirate will make all his rolls next round at -4 to DX and IQ. Plus, he's taken some damage, so he halves his move and dodge (making them 3 and 6). This is from being at less than 1/3 hit points. For being at 0 hit points he makes a HT roll at the end of every one of his turns unless he takes do nothing maneuvers and makes no active defense rolls. This continues until he is not at 0 hit points. If he fails he passes out. For every full multiple of his HP (-13, -26, -39, etc) into the negatives he gets, he'll make the roll at a -1.
Our dragon still has one attack maneuver left, so he swipes at our actual pirate with a claw and rolls an 8 against his skill of 16. The actual pirate rolls 10 against his adjusted dodge of 6. Several things happen like they did on the last attack with the net result being our pirate takes an another 9 damage, putting him at -9 HP. This changes nothing from the statistics given above.
But wait, there's more. The dragon has a poisonous bite that does stuff. The damage from its bite got through the actual pirate's Damage Resistance, and the Affliction for the venom is a follow-up attack to the dragon's bite, so it automatically hits the actual pirate and he has to make a HT-2 roll. He rolled a 7 against his adjusted HT of 10, so he resists the toxin coursing through his bloodstream. It's probably easier because all of the blood is pouring out of his body instead of lingering in his circulatory system.
The Sereth takes his shot and rolls an 8 against his Guns skill of 22 (16 base, -9 for targeting the eye, +8 from the aim maneuver, +5 for the dragon's SM, +1 for the Weapon Bond perk, and +1 for his bracers) and puts a silenced round into its eye. He deals 27 damage, which manages to punch through the dragon's scales for 6 damage. This blinds the eye (giving the dragon the One Eye disadvantage) and multiplies the damage by 4 for 24 damage, reducing the dragon to 7 hit points. Meaning its move and dodge are halved (4 and 6). The dragon doesn't take the -4 shock penalty due to have High Pain Threshold.
It's our actual pirate's turn again, so he takes move maneuver and pays a FP (reducing him to 13 FP), and moves straight up 3 yards into the air, away from the dragon. Then he rolls a 9 against his HT of 12 and remains conscious.
The sorcerer is up and takes a concentrate maneuver and puts two more energy into his spell (4 total) and casts it through his revolver at the dragon. He rolls a 7 against his Innate Attack skill of 17 (14 base, -3 for distance, +1 for revolver giving him an increased reach, and +5 for the dragon's SM). The dragon rolls an 11 against its adjusted dodge of 6, a hit, and a ball of fire smacks it in the side and deals 18 burning damage, which the thick scales totally rebuff.
The Elduman's turn rolls around and he derps around on the ground, but manages to roll a 7 against his HT of 10 to recover his wits.
At the bottom of the second round, we have the actual pirate at -9 HP and 13 FP. We have the Elduman on the ground looking less dazed and at 4 hit points, the sorcerer feeling some performance anxiety, and the Sereth looking smug.
The dragon has one eye now, so he's at -1 DX in combat. So his speed drops to 7.75 (he still goes first), his move drops to 7 and is halved to 4. His dodge is 10 and halved to 5 and his Brawling skill drops to 15.
The dragon makes a move and attack maneuver and charges towards the Sereth and rolls a 9 against his adjusted Brawling of 9 as it tries to bite the bullet slinging fuck in half. The Sereth rolls a 12 against his dodge of 10. Ouchie. The dragon does 6 cutting damage (seriously?! two 1s and a 4? fuck off dice roller app!) which impacts the Hound's hide armor's DR of 4. Eran ends up taking 3 damage (because of the 1.5 multiplier of cutting damage), which reduces him to 9 HP. He looks up at the actual pirate with a confused expression on his face as if to say, "What's the big deal?"
As if feeling some manner of performance anxiety, the dragon seeks to compensate for that display and slashes at the Sereth with its claws. It rolls a 4. Ahem. Well. That would be a critical hit, so the Sereth doesn't get a defense against it. I did not intend for that to happen and I wrote the Sereth's smarminess in before rolling it. So yeah, the dragon rolls 3d on the critical hit table and gets an 11, which is normal damage. That was anti-climactic. So the dragon rolls 3d+1 for its slash and deals 14 cutting damage, which drops to 10 after DR and jumps back up to 15 once it hits flesh. This drops the Sereth to -9 hit points. Oh look, he and the actual pirate can be bleeding their guts out besties.
So now the Sereth has the -4 to DX and IQ shock penalty. He also rolls a 12 against his HT of 12 because he took a major wound (injury equal to 1/2 his hit points or more) and avoids being knocked down and stunned like the Elduman was. Because he's at less than 1/3 of HP, he also halves his move and dodge down to 3 and 6. Because he's at 0 or less HP, he'll have to make a HT roll to remain conscious if he decides to do anything other than a do nothing maneuver on his turn.
With its dominance once more established, the dragon spits a gob of acid towards the actual pirate and rolls a 16 against its adjusted Innate Attack skill of 15 (16 normally, -1 for the actual pirate being 6 yards away). A miss.
It's the Sereth's turn now so he decides to take a ready maneuver and drink a potion, he also steps back one yard from the dragon. He rolls a 7 against his HT of 12 and remains conscious. The potion (lovingly crafted by the sorcerer healer bro bro) restores 4 hit points, bringing the Sereth up to -5 HP. Wooo!
Planning to essentially do the same thing, the actual pirate rolls an 11 against his HT of 12 and remains conscious to quaff a potion. The potion restores 3 HP, bringing him to -6. He also flies another yard up and away from the dragon.
The sorcerer takes a concentrate maneuver and steps towards the Sereth, poking him in the shoulder with the barrel of his revolver. He draws 4 energy from the sorcerous energy of the environment and rolls a 10 against his skill of 16 with the major healing spell. Because his skill level is so high, the cost drops to 3 and leaves 14 sorcerous energy accumulated around him (10 from concentrating to cast fireball, 10 from concentrating to cast major healing, -4 for fireball, -4 from major healing, +1 refund for skill level from fireball, +1 refund for skill level from major healing). Sorcerous energy hazes around the Sereth and he heals 8 HP, bringing him to 3 HP.
The Elduman still lying on the ground and somewhat leery of drawing the dragon's attention again, pays 3 energy (reducing him to 3 in his reserve) and activates his telekinesis for a minute and grabs a grenade from the actual pirate's belt and hurls it at the dragon from above. The grenade is a special one made by a short one-eyed chemist the group knows, it just explodes when jostled to much. The Elduman rolls a 10 against his effective Throwing skill of 13 (base of 8 for defaulting to DX-3, +5 for the dragon's SM). The dragon, still focused on the actual pirate, sees the shimmering force and the small object, and it rolls a 15 against its dodge of 6 and the grenade smacks it in the back. The grenade explodes, dealing 32 crushing damage to the dragon, which is reduced to 11 points of damage, dropping the dragon to -5 HP.
So at the bottom of the second round, everyone is still kicking and the dragon is down to -5 HP.
The dragon, having never encountered the flaming nonsense of a grenade, and never having been injured this much in three seconds of battle before, and being a big animal that is moderately intelligent, and being a figment of the deity's memories, retreats. The group, being somewhat worse for the wear, but not dead, decide to not hunt down the giant lizard in an illusory forest inside a deity's brain space. The actual pirate drinks heavily over the course of several ready maneuvers.
This is just an example of actual GURPS combat, all the rolls are legit. It was equal parts playtest and educational example. There are a few things to remember though.
The first is that the player characters are made as a translation, not a conversion. I took Pathfinder created characters and translated them the best I could to GURPS. What I mean by this is that in Pathfinder, Psions use Intelligence as their primary statistic, whereas in GURPS, psionics mostly use the Malediction modifier, which bases their powers off of Will. So instead of having a 13 in Will for 15 points, Donovan has an IQ of 13 for 60 points and a Will of 10 for -15 because his Wisdom was 10 in Pathfinder. If Donovan had been built from the ground up in GURPS, he would look differently.
The second thing to remember is that I gave the dragon it's full Damage Resistance on its eye hit location, instead of its Nictitating Membrane DR. This means that Eran's first shot would have done around 80 damage and put the dragon at -49 hit points. Which means a HT save or die, then another one at -62.
The third thing is that a DR of 21 is way the fuck high. If this had been a campaign event, I would have tweaked it so the small caliber revolvers the group carries could penetrate it. If we want to go the "realistic" route, creatures with scales or shells should have the Semi-Ablative, -20% modifier on their Damage Resistance, which would mean that every ten points of damage dealt to the creature reduces its innate DR by 1.
Fourth thing, hand grenades deal explosion damage. This is special because when you total the damage and deal it to the target (if there is one), you then divide it by 3 times the number of yards bystanders are from the explosion site, rounding down. So everyone within one yard of the dragon would have taken 10 crushing damage, everyone within two yards would take 5 crushing, everyone within three yards would take 3 crushing, within four to five yards would take 2, six to ten yards would take 1.
I also didn't muck about with the retreat option for an active defense. If you are attacked with a melee weapon, you can take a step move (basic move/10, but never less than 1 yard) and gain +3 to your dodge defense, but you're are still vulnerable to their close range melee attacks.
I also did not do anything with armor piercing rounds, which the Pathfinder version of the group has access to, which would have given Karrak's revolver a chance of actually damaging the dragon. I also didn't have Karl or Karrak fan hammers or thumb to increase their shots per round (and thus their chances of high damage, though this is only relevant if I had given them armor piercing rounds). If we're being honest, I also fudged the whole psychic crush thing that occurred on the first round because I didn't want to repeat the Pathfinder battle. I also had Eran aim instead of just shooting the dragon on the first round, he had plenty of bonus without the +8. I made these choices because I wanted to give everyone a chance to do something in GURPS.
I also fudged several maneuvers. With Donovan's telekinesis and the grenade I handwaved that Donovan already had it activated in my head (which takes a ready maneuver, just as it should have for Karrak to start walking on air) but it also takes a ready maneuver to pick up an object to throw with telekinesis, so Donovan wouldn't have been able to throw the grenade until the third round. Karrak's Buffered By the Sky also got fudged. I think you can use it in addition to making an active defense like a dodge, but I'm not 100% positive. However, if you use it more than once per round you get a cumulative -4 penalty to it every time you use it after the first. I didn't include the rolls in the second round where he gets dropped from 0 to -9 HP, but reducing his chance to activate Buffered By the Sky would have failed if he had done it with a -4 penalty, which would have put him at -13 HP and forced a HT roll to not die.
This wasn't a totally legit GURPS fight, but it is a much better example than the previous test battle from a few years ago where the Doctor rapid fired lasers at the Robot and reduced him to 0 HP and I thought he was dead. Additionally, I probably forgot a modifier or thirty somewhere in there. I wrote this post in the back of a moving ambulance rattling around on I-75 and using my phone as reference, dice roller, and calculator.