Wreaking Havok
Civil Protection Officer: "Pick up that can."
Gordon Frohman: "How the heck do I do that? Oh. Whoah! I can pick up things in this game! ...I mean, world."
Prominent exercises in game physics for the sake of it.
Since the first release of the Havok engine in 2000, it's been the go-to software for developers looking to add a little verisimilitude to their worlds—it allows crates to stack realistically, chains to swing convincingly, and corpses to collapse satisfyingly. Its success inspired the creation of several other physics engines.
But, like nuclear power, a physics engine can also be used with reckless abandon. Sometimes the developers, giddy with the possibilities afforded them by real-time collision modeling, become drunk with power. You'll run across applications of the physics engine that shout "Hey! Check out these physics!" so loudly it comes dangerously close to breaking the fourth wall.
These exercises in game physics conspicuously draw attention to themselves rather than meshing with the rest of the game. Note that this isn't necessarily a bad thing—in some cases, playing with the physics doesn't mesh well with the rest of the experience because it's more fun than the actual game.
If you're playing a game that puts a Gravity Gun in your hands, expect to run across a lot of these. Depending on the circumstances, Wreaking Havok may qualify as a form of Benevolent or Malevolent Architecture.
- Example the first: knocking out a support beam, causing a chunk of the ceiling to crash down on a see-saw and launching you into the air toward the next section of the level.
- Example the second: knocking out a support beam, causing a chunk of the ceiling to crash down on you.
It's also a common feature in latter-day Block Puzzles.
As well as Havok there is the Bullet engine, nVidia's PhysX, NewtonDynamics, and many more. It's just that Havok is the most prominent. And Wreaking Bullet sounds like More Dakka. See also Tech Demo Game.
Action Adventure Games
- Exile (not that one) has a sophisticated physics engine for a 1988 BBC Micro game. It's still impressive for the age on its Commodore 64/Amiga/AtariST ports.
- One of the bonus videos with Uncharted 2 has a section named after this trope, and various set-pieces make use of it.
- Lego Harry Potter lets you kick Lego bits around the room, levitate them, etc.
- Hydrophobia is essentially a game based around water.
- Super Mario 64 features a primitive form of this trope. The first level contains a completely unnecessary bridge that seesaws when Mario steps on it. Why? Because it was damned impressive by 1996 standards, that's why.
- Likewise seen in Jazz Jackrabbit 1 where the first world has a load of swing bridges that are almost never seen again in the game.
Action Games
- PAIN is not much more than a Havok demo. You score points by flinging your ragdoll at bits of scenery, many of which break or collapse using the physics engine, scoring additional points. Add some Dead Baby Comedy and that's the whole game.
- Pretty much the entire point of the Breakout clone Break Quest are the advanced physics.
- Star Wars: The Force Unleashed is made of this, to the point where developer interviews prior to the game's release focused pretty much exclusively on the awesomeness of the physics.
Beat Em Ups
- Super Smash Bros. Brawl has it. Before the release of Brawl, it was briefly on Havok's list of games that use the engine, but quickly taken off. It's definitely in the game though, as the logo appears in the adventure mode's credits, and a few items (the wheeled crates and soccer balls in particular) seem designed specifically to show off the physics.
- It's possible they also used Havok to model the physics involved in tossing opponents into each other, although this feature was also present in Melee.
- Lugaru's physics modeling is goofy but fun. Kicking enemies into each other nets you a "Nice Aim!" bonus, downed enemies struck with a bo staff will sometimes launch hundreds of feet straight up into the air, and ragdolling yourself with the Leg Cannon attack and tumbling down hills never gets old. Overgrowth looks to continue the tradition, but with more complex ragdolls and objects.
- Amusingly, Lugaru's physics extends to activities that are impossible without cheating. If you cheat up Turner's strength to a hundred times its normal value, you'll find that enemies explode after they get Punched Across the Room and hit a wall.
Driving Games
- Burnout. Each wreck is punctuated by a super-slo-mo sequence designed to showcase the awesome crash physics. Crash Mode takes it a step farther, requiring that the player make clever use of crash physics to destroy a freeway full of vehicles.
- Flat Out ups the ante as almost anything breaks into pieces when crashed into them.
- Need for Speed: Hot Pursuit would count since it's made by Criterion (Which they were behind Burnout), sometimes during the crash scene, your car can be sent flying by another racer or cop as it careens into it.
- Wheelman went as far as to name one of its Achievements Wreaking Havok.
- Stuntman: Ignition would be rubbish were it not for the sheer fun of the physics engine.
- Need For Speed: Shift has amazing head physics, where crashes and sharp turns alter your view as g-forces are applied to the drivers head.
- Rigs of Rods is this trope, if the car is made and scripted correctly (such as ones by Gabester like the Gavril Omega or Honda Hatchback), it will deform similar to a real car when it is crashed. Bumpers, hoods, trunk lids and doors can fall off. It helps even better that you can toss your car around like a child would to his toy by clicking and dragging
First-Person Shooter
- Easily the earliest examples, predating physics engines themselves by many years, came with games based on the Build engine. Duke Nukem 3D included a pool table with balls that would move around realistically and even fall into the pockets when fired upon, while Blood featured the ability to kick severed zombie heads around like soccer balls.
- Half-Life 2, which might be the Trope Codifier, contains heaps of physics puzzles, from piling cinder blocks on see-saws to placing buoyant barrels under an aquatic ramp to removing cinder blocks from a pulley system (not to mention the carelessly dropped can from the quote above). And these all occur before you get the Gravity Gun. One wonders whether every member of the Resistance fleeing from City 17 had to pass the same series of puzzles, or whether this was an elaborate obstacle course set up to determine whether Gordon Freeman was truly the Chosen One...
- Justified in the Ravenholm level, in which some of the puzzles are clearly traps set up by the Ax Crazy Awesome Father Grigori. The scarcity of ammo pickups in Ravenholm also require you to lean heavily on your shiny new Gravity Gun, which was also totally an excuse to chop zombies in half with big-ass sawblades.
- Doom 3 has the occasional corpse hanging from a ceiling, and they make very tempting piñatas, except that, when they asplode, they shower you with blood instead of candy. The Resurrection of Evil expansion pack introduces its own version of the gravity gun, and things got really interesting.
- In an interview, it's revealed that they used their version of the gravity gun to create the damaged areas in Doom 3. You're armed with a Developer weapon in the expansion.
- Hilariously, it was removed from the initial release of the main game because, despite being not only useful for the devs but also fun for them to goof around, they thought it would be an annoying distraction for players. The next year, when Half-Life 2 was released, they regretted it enough to add it to RoE.
- Used in BioShock (series). You can knock over things, chip the walls, break shop windows (which summons a security alert), and when you get the Telekinesis plasmid, you can start throwing random debris at Splicers. Or you can pull their masks off and beat them to death with them.
- Telekenesis is also one of the three plasmids you have to get to beat the game, despite it being near useless for everything other than the Broken Bridge you need it to cross. Coincidence?
- Painkiller's third boss, in an impressive demonstration of Malevolent Architecture, effortlessly smashes his way through ancient arches and spires, scattering the debris all over the place. On the other hand, this tactic is more annoying than hazardous, since the gigantic blocks of solid rock are somehow completely unable to damage the main character even if they land directly on him from 30m high.
- Speaking of grabbing other people and throwing them, this is one of the most amusing ways to kill your enemies in Crysis. You can also throw them off of cliffs... or into trees... or you can throw trees at them...
- An early example exists in Jurassic Park: Trespasser, with the player character able to pick up objects and throw them or use them to hit dinosaurs over the head, and some primitive physics puzzles. The excellent Let's Play by Research Indicates explores how
wellbadly this was actually implemented - notably, most of the puzzles consist of 'knock over single stack of crates' and friction is nonexistent.- The way their system was set up, each interactive physics object was encased in an invisible box that would approximate the item's collision detection data, and when two items' respective boxes collided with one-another, they would start pushing each other away at the collision point until they were no longer colliding. Unfortunately, this made it extremely difficult to properly simulate any object that wasn't a box the size of one cubic metre, and stacking objects on top of one another was almost impossible, so the developers' ideas for item stacking puzzles went straight out of the window. A similar system was also used to procedurally animate the game's dinosaurs, with each of the dinosaurs' limbs acting as a separate physics object, avoiding a very canned/artificial look to the animation common to other games of the time...
- ...which sometimes resulted in velociraptors ending up with spring-loaded heads trapped inside their torsos in addition to walking like they had 200-proof alcohol for blood, and the physics processing for the dinosaurs took so much resources that they couldn't have more than seven dinosaurs per level. Man, was that game an Obvious Beta.
- It could have been incredibly awesome, if they had set their sights lower. Unfortunately a bad case of Feature Creep consigned it directly to Development Hell.
- The way their system was set up, each interactive physics object was encased in an invisible box that would approximate the item's collision detection data, and when two items' respective boxes collided with one-another, they would start pushing each other away at the collision point until they were no longer colliding. Unfortunately, this made it extremely difficult to properly simulate any object that wasn't a box the size of one cubic metre, and stacking objects on top of one another was almost impossible, so the developers' ideas for item stacking puzzles went straight out of the window. A similar system was also used to procedurally animate the game's dinosaurs, with each of the dinosaurs' limbs acting as a separate physics object, avoiding a very canned/artificial look to the animation common to other games of the time...
- In Star Wars: Dark Forces: Jedi Knight: Jedi Outcast, using force powers to throw stormtroopers et al. about was easily the most fun part of the game.
- Garry's Mod allows you to go somewhat overboard with this trope. It can be a bit too easy to slow your game to a crawl and it's entirely possible to crash it by abusing this trope too much. Try filling a shipping container with loose objects and you'll have the game running so slow that it'll be unplayable long before you fill the container.
- Perfect Dark has a very primitive physics engine. It could be used to provide limited cover in some levels, but the only time the creators used this deliberately was in the last level, with the piece of rubble that had to be pushed over a switch.
- First Encounter Assault Recon has such a conspicuous physics system you really have to wonder which came first: its horror setting or its physics engine. To clarify, this is a game where objects moving by themselves are meant to creep the player out. Only the thing is, the player model itself is rendered in-game (despite the game being first person), and the player model is in itself a physical object. What this means practically is that you'll constantly find yourself bumping into things and knocking stuff off of shelves like the clumsiest special forces operative in history. Sometimes you'll hear something you just knocked loose making a noise you can't see and whip around thinking something is trying to sneak up on you. On top of that, the physics are prone to glitching when dealing with heavy inanimate objects, like corpses, falling in piles atop each other. They'll often drop to the ground and then begin bouncing off the ground and another object that fell on top of them, starting to bounce up and down very quickly and making a ton of noise. And that's not even getting into the tendency for a corpse's limbs to embed themselves into a wall.
- Crysis suffers from such dodgy physics as well—considering the at first, cool idea of making some structures completely destructible, you end up either trying not to, or simply getting out of the area as quickly as possible- before the rattling metal drives you insane.
- Deus Ex Invisible War is one of the earlier games to use the Havok engine to manipulate most of the game-world's object. The problem is that most objects' weight were set way too light, which led to many amusing (and annoying) results. This also make simple tasks like stacking up two (or more) boxes to reach higher places almost impossible, since they roll/fly away at the slightest touch. Oddly there are no balls to play with on the many pool tables found in the game, which exist in the first game.
- Judging from this, Battlefield 3 has this trope in spades.
- Halo's Forge lets player add new items to a map even when there is an ongoing match, resulting in such tactics as having one player fly around holding a box while a second player uses it as a mobile sniper spot.
Light Gun Games
- Razing Storm has very destructible environments: Besides crates, cash registers, watermelons and stuff, you can blow up part of a building, killing the terrorists on it... with a machine gun, no less.
Platform Games
- Rather overbearing (no pun intended) in Banjo-Kazooie Nuts and Bolts where the player's vehicle will often tumble uncontrollably when attempting to drive over anything that isn't a flat surface.
- Players have messed around with the vehicle creation system and physics engine to create everything from Humongous Bipedal Mecha, Transforming Humongous Bipedal Mecha, all matter of flying machines, and even a car that can drive on walls and the ceiling.
- Then there is the Kinetikos.H featured in Rooreeloo's Let's Play of the game, which runs specifically because of the Havok engine's screwy physics.
- Silver the Hedgehog's psychokinetic gameplay in |Sonic '06 is enabled by the Havok Engine and is treated with as much reverence and respect as the rest of the game. Silver, at first was indeed planned to showcase the Havok physics engine. And did. Poorly.
- This seems to be a prevalent problem throughout the entire game. Watch this and laugh. "Physics? What are those?"
- During their infamous Let's Play, pokecapn and crew note that normally when a physics object is destroyed the pieces seem to lack mass and drift ponderously to the ground—with the exception of one specific section where the physics reactions are scripted and meant to be obstacles, when they slam down at warp speed.
- This is the entire point of Trine. It wears thin after a while, although the Scenery Porn helps make up for it.
- It wears especially thin when the mage gains the ability of summoning floating platforms, negating any need to figure out a way to beat the physical obstacles below.
- Gish is a 2D platformer with extensive use of physics. Titular main character especially.
- Rocket Robot On Wheels had a dedicated universal physics engine, before Havok. Notably, because its main character's primary means of attack is picking things up with a Tractor Beam. (However, it also makes for nice platforming.)
- The original Sega Genesis Sonic the Hedgehog games had a rather advanced physics engine for the time to go along with the games' great speed, as Sonic could realistically pick up speed from rolling down a hill. This is most noticeable in the original game, where Sonic rolls down a pipe and gets launched up a ramp hundreds of feet into the huge pile of rings.
Puzzle Games
- Boom Blox almost qualifies as an inversion; whereas most applications of Wreaking Havok involve the physics engine intruding upon the game's atmosphere, the story mode in Boom Blox tacks a completely unnecessary plot onto the abstract, physics-based gameplay. It's as though they came up with a story mode for Tetris.
- Garbage disposing puzzle game Trash Panic has havok physics. It's possible (though rare) to accidentally create a see-saw design and send something undamaged flying out of the can (which costs a life). It's got soccer balls too.
- Stair Dismount is one of the earliest examples, developed in 2002 with the goal of using the interactive physics engine to throw a ragdoll down some stairs and causing as much damage as possible.
- Ballance uses this throughout, most visibly with your own ball, which changes weight throughout the game, becoming harder or easier to maneuver on the variably sloped surfaces. The crates and other obstacles you push out of your way obey rigid body physics as well, tumbling spectacularly off the thin platforms down into the abyss.
- Portal takes this trope and turns it on its head, sideways, and every other direction you can think of.
Real-Time Strategy
- Ever tried shooting with artillery in Age of Empires III? It was the first Real Time Strategy game to come up with Havok physics, and uses it everywhere,
so long aswhether or not it makes sense. Examples include blasting a house to more splinters than could possibly have been in its space or flinging an unaware rider a good hundred feet off his horse. - Total Annihilation was one of the earliest RTS games to feature any physics modeling at all that wasn't a graphical shorthand. All unguided projectiles had ballistic trajectories and debris flight paths were modeled in real time. The fixed overhead camera really wasn't the best way to show it off, however.
Role-Playing Games
- Dark Messiah has a bunch of physics traps triggered by cutting rope or kicking loose boards. You can also use a Telekinesis spell—basically a magic-fueled Gravity Gun—to fling boxes and barrels around (The limit break for the spell makes people a valid target).
- The Elder Scrolls IV: Oblivion slips into Wreaking Havok territory early in the game. Part of the tutorial, if you pick up the bow, asks you to shoot a target with an arrow. Had the target been anything but a hanging bucket, the incident probably would have passed unnoticed; since it is a hanging bucket, which jostles around amusingly on the end of its rope and hangs differently from the weight of the arrow stuck in it, it's obvious that Bethesda was using the opportunity to show off the physics engine. To Bethesda's credit, the game only prompts you to do this if you pick up the bow in the room, which is entirely optional.
- At other points in the game, the physics engine mostly leads to you knocking everything off the tables when you so much as walk slowly by them.
- And God help you if you decide to decide to engage in a little home decorating. Trying to place a book on a shelf could result in everything else on that shelf ending up halfway across the room. It gets even worse if you have the Game Mod that makes most objects in the game use physics. If you dare to pick up a book from a bookshelf, expect it to collapse down on you within the next five seconds.
- A big part of the fun of the first dragon shout you receive in Skyrim, Unrelenting Force, is to let it loose in a place filled with objects (such as a dinner table) and see where everything ends up after being blown across the room.
- Skyrim also manages to reach such a level of detail that it ends up making its physics engine look bad. Most of this is due to the fact that said physics engine appears to have no support for friction, which is pretty important when fighting things on uneven terrain. For instance, killing something on a hill will result in the body unceremoniously sliding down the hill, as opposed to rolling down it.
- At other points in the game, the physics engine mostly leads to you knocking everything off the tables when you so much as walk slowly by them.
- Fallout 3: A bit of this appears. One of the items you can build is the "Rock-It Launcher," a high-powered leaf-blower that shoots your accumulated inventory clutter as ammo. The ability to decapitate raiders with high-speed teddy bears is both hilarious and fun.
- The game also features an elaborate physics-based trap in a grocery store that involves explosives, a baseball launcher, a series of dominoes, and a swinging battering ram. It takes forever to run its course, and you know the instant you set it off that it's not going to turn out well, but the unpredictability of both Havok and the game itself means that there are plenty of opportunities for it to fail, even if it doesn't kill you in the process.
- The NPC with the best sniper rifle in the game likes to take potshots at people from a bell tower. Killing him may or may not cause him to fall down the hole in the floor to a location where you can loot the rifle, entirely depending on Havok's mood. Since the game treats gibs as lootable, the easiest way to get the rifle is therefore to launch a rocket in the bell tower window. With any luck, the NPC will be gibbed, virtually guaranteeing that of all the Havok-ed gibs at least one will fall through the hole.
- Dawn of Mana was widely derided by critics as being a "glorified Havok tech demo." Most of the gameplay consists of hitting boxes with a whip to gain power ups. (Losing those precious powerups at the end of every chapter didn't help.)
- By that measure, Children of Mana would also qualify. Most of the gameplay involves hitting enemies with a hammer so that everything it touches will bounce off of as many surfaces as possible.
- Final Fantasy Crystal Chronicles: The Crystal Bearers is basically the same exact game as Dawn, only the protagonists are a couple years older. And instead of whipping objects, you grab them with telekinesis, flick them away, haul them up, throw them at monsters, throw monsters at monsters, and so on. Certain monsters have tricks to them. You can spin an Electric Jellyfish to make it discharge electricity, pick up an archer and have it fire on other monsters, or thorw stuff at a Bomb and watch it blow.
- Mass Effect series:
- Mass Effect dips its toes into Wreaking Havok territory from time to time, which is only to be expected when the universe's equivalent of magic is all about manipulating gravity. High-level biotics can turn entire rooms into swirling maelstroms of corpses and furniture. Living people can also be tossed about quite easily, although this one can be less entertaining and more annoying when someone inevitably gets stuck in a wall.
- Oddly downplayed in Mass Effect 2, when Biotics don't have anywhere near that much ability affect the environment. They did, however, have a scene in the opening level where you're in a destroyed space ship without gravity, complete with pieces of wreckage that go flying away at the slightest touch.
- Demon's Souls utilizes the Havok physics engine, and puts it to good use by liberally populating levels with tables, chairs, shelves, boxes, barrels, and other breakable objects begging to be smashed to pieces. Users of the game's numerous BFS's and other large weapons can leave an impressive trail of destruction in their wake without even trying.
Third-Person Shooter
- Max Payne 2 does this early in the game when one of the first mooks you encounter runs into the room and past a freestanding shelf filled with little boxes and cans. Cue the gratuitous slo-mo shot of said mook being hit by your bullets, thrown back, colliding with the shelf, knocking it over, and collapsing on the floor in a shower of said boxes and cans.
- Also, ammunition, for some absurd reason buried under a chaotic mountain of Havok driven plastic chairs with a grenade positioned next to it.
- At a certain point in the game you come across several baddies who haven't noticed you. They are in a room with several gas cylinders nearby. Outside the room there is another gas cylinder, this one lying on the ground, with the gas nozzle pointing away from the doorway. You can just go in guns blazing and kill the mooks the good ol' way, but the awesome way to do it is to shoot at the cylinder's gas nozzle. The cylinder will then ignite, rocket inside the room and blow up. What enemies aren't killed by that will be killed by the explosion of the other cylinders, ignited by the first one. This happens several times in the first game, as well.
- There's an out-of-the-way room in Mona's funhouse (the abandoned Address Unknown attraction) that is explicitly designed to allow the player to play around with the physics engine. It has no other purpose with relation to the rest of the game.
- Alan Wake uses this when the Dark Presence starts possessing objects and throwing them at you. The physics can look quite amazing when seen on a large scale, but the engine shows you its true potential during the very last level, when the Dark Presence starts pulling objects up from the bottom of the lake and throwing them all at you in a last ditch effort to stop Alan. Said objects include several trucks, A LOT of building debris, and a boat. As in a fairly decent sailboat. Yeah.
- Also, when you get the train car thrown at you from the top of a hill, and you have to run like hell to avoid getting crushed by it, Indiana Jones style
- Second Sight eventually gives you telekinesis, which is great for this sort of thing, but you don't really have to wait until then. In the first mission (after the tutorial level), there are loose crates and chairs. If you happen to run a little too close, you can wind up kicking them down the hall. And if they happen to hit some enemies, you might find your suspension of disbelief slightly strained when you wind up killing them by accident.
- The entire game Fracture is not much more than a big tech demo for the developers' Deformable Terrain engine.
- Ghostbusters. Ghostbusters, Ghostbusters, GHOSTBUSTERS. The game whose state-of-the-art engine allows you to draw capture streams around ghosts (in past games, the ghosts would just get "stuck" in your streams) and destroy the scenery around you in real-time . Not just context-specific bits of scenery; all of it.
Turn-Based Tactics
- Silent Storm was possibly one of the first of it's genre to utilize modern FPS-levels of physics. Shooting a wall at a shallow angle will make the bullet ricochet off while shooting it head-on make rifle bullets go clean through the wall and hit whoever is standing behind it, just like in the real world. In fact, every single weapon other than explosives and pistols are capable of over-penetrating whatever happens to be in the way: doors, fences, corpses... Speaking of which, it's not rare at all to see someone's ragdoll be knocked a few meters backwards by a kill shot from a rifle.
And we haven't even mentioned the 100% destructible terrain: locked doors can be shot to pieces with just a lowly submachine gun instead of picking the lock and explosive Disaster Dominoes can demolish entire buildings (although you DO get a Nonstandard Game Over for excessively over-the-top collateral damage). Also, shooting through obstacles is an entirely valid strategy; the Sniper class even has an early perk that completely removes the advantage of cover for the target!
Wide Open Sandbox
- Destroy All Humans! Just screams havok.
- The deformable terrain in the Red Faction series. And the destructible buildings in Red Faction: Guerrilla.
- Saints Row 2 generally uses Havok for relatively sensible things -- ragdoll corpses, explosions, car crashes, etc. -- but there's an "Insurance Fraud" Mini Game in which you have to fling yourself in front of traffic and attempt to bounce from car to car in the most painful way possible. It is deliriously entertaining.
- Just Cause 2 introduced the Double Hook (over the first game's simple grappling-hook) mostly just to show off the Havok engine. It allows you to basically attach any two objects to one another. Attach an enemy to the ceiling, watch him bop around while you use him as a pinata... attach the head of a dictator's statue to the back of your car and hit the gas to watch the statue topple and shatter - then continue down the road, dragging the head behind you. The possibilities are endless, and not all of them are well-executed... for example, if you attach your car to the tail of a jumbo-jet about to take off, your car will swing wildly under the aircraft once in flight, picking up more and more speed until it finally does a complete loop-the-loop over the wings of the plane...
- Most of Carmageddon's fun comes from the unrealistic but awesome physics, which allow you to roll boulders over your opponents, sling pedestrians into each other, and so forth. The Pinball Mode powerup cranks this Up to Eleven, causing all objects to ricochet off one another with increasing speed; confined spaces become deadly, shrapnel-filled Bouncy Castles.
- Dwarf Fortress has fluid dynamics that differ subtly between water and magma. You are advised to learn their differences well, lest ye flood your fortress. They're both quite useful if you want to build a Doomsday Device.
Massively Multiplayer
- Vindictus may be the first MMO to have fully functioning physics (powered by Valve's Source engine, in fact, which uses Havok extensively) and is quite proud of the fact. Many of the higher-tier weapons and armor are covered in chains and baubles that swing about as the player moves, and one of the highlights of the combat system is the ability to pick up random objects and use them as Improvised Weapons, such as pots or chunks of stone or mid-sized trees. Hilarity Ensues.
- Dragon Nest actually used Havok earlier but advertised it less, probably because the object destructions seem to have been just pre-rendered with the engine.
- Second Life pre-dates Vindictus by about six and a half years. Its Wide Open Sandbox nature and physics engine permit players to create all sorts of interesting situations, although some exercises, such as a ten-link chain, have been known to wreck havoc upon the server's CPU. (The chain in question did sway quite convincingly, at about a frame every five seconds.)