Games require rules. Even Calvin Ball has a few (You can't play it the same way twice, you must wear a mask, and you are not allowed to question the masks). Most of the rules are simple, especially in simple games, like tag. But then, there's That One Rule.
It's the one exception, it's complicated, it can get most people arguing over how long players can stay on base without getting tagged.
Whether these rules are caused by an Obvious Rule Patch or just a bad design decision, most players (or fans, in the case of sports) learning the game will wind up confused by this rule; particularly spectacular examples will confuse (and be hated by) advanced players.
The point here is that this is a case where most of the rules are very easy to understand except for a rule, or a few rules, that are glaringly complicated.
Differs from Loads and Loads of Rules in that this is a localized case of the problem. See also Grappling with Grappling Rules, an example from tabletop RPGs. Not to be confused with Scrappy Mechanic, which is not about a game rule or mechanic being complex or confusing, but about it being outright hated - a rule can be both overly-complicated and hated.
- Castling and en passant capture are confusing to many Chess players.
- Castling is moving both the king and one of his rooks, the only move allowed in chess where two pieces are moved in the same move. The list of circumstances that must be met is rather long, but it's easy to determine whether all of them have been met or not. The simple version is: Neither the king nor the rook can have been moved at all, at any point earlier in the game. All the intervening squares in the home row must be vacant. The king cannot move through a square where he would be under attack if he were to stop there. You cannot castle to escape check. You cannot castle into check (though you can deliver check or even checkmate). You cannot capture in the course of castling. You cannot un-castle or re-castle.
- The en passant ("in passing") capture is — Well, it's this: "It can only occur when a player exercises his option to move his pawn two squares on its initial movement and that move places his pawn next to the opponent's pawn. When this happens, the opposing player has the option to use his pawn to take the moved pawn "en passant" or "in passing" as if the pawn had only moved one square. This option, though, only stays open for one move." The biggest point of confusion for lower and mid-level players is that it's not the player who moves forward two squares which can capture en passant, it's the opponent, on their next move.
- Tournament Players probably don't have any confusion about castling or en passant; for them That One Rule is the long-evolving set of rules about when they are allowed to claim a position as drawn.
- The board game of Go has extremely simple rules...
- Except for the "ko rule" which is designed to prevent repeating positions. In the simplest form it just disallows one specific position which is sufficient for 99.9% of all games. The Ing Ko Rule resolves the other .1%, at the expense of pages and pages of explication.
- Endgame scoring under the Japanese rule set can also be problematic in certain situations, because if a group is dead in the endgame, the killer doesn't have to capture it. Sometimes, however, whether a position is dead or not is in dispute, because the position is not truly alive with two eyes, but the attacker could not capture it even in the endgame; the most common situation where this would happen is with a shape called a "bent four in the corner," which can only be captured through a ko fight, which is a bit unpredictable, and resolving ko in the endgame is a source of major rules disputes.
- Japanese Mahjong: The rule that a hand with no value has some value. Explanation:Yaku give "multiplier" (han) points which are applied to the "basic" (fu) points of the hand. A hand with the absolute minimum of fu counts as a yaku as this is actually quite tricky to do, and is therefore a valid hand to win with. And then you add that, under some circumstances, you need more than one yaku to win.
- Some of the mechanics of Magic: The Gathering are like this.
- A few old-school cards have very complex rulings because they were made before making sure that there was no room for interpretation became one of the game's priorities; see for example Ice Cauldron or Word of Command. However, the absolute worst part of the rules is what happens when there are multiple persistent abilities that affect what a card can do, epitomized by the interaction between Humility and Opalescence. Witness the block of rule clarification on the interaction between those two cards specifically, as well as how many times those rulings have changed.
- The so-called "infinity rule" is responsible for plenty of headaches. For example, if one player can do an arbitrarily large amount of damage, and another player can prevent an arbitrarily large amount of damage, things get ugly. (Would you believe that the outcome depends on whose turn it is?)
- The rule that disallows players from reordering the cards in their graveyards. This can interfere with effects that count cards of a certain type in graveyards, and forced players to pay strict attention to resolution order when placing cards in graveyards (for example, Day of Judgment must go on top of the creatures it destroys). All this for only a handful of infrequently-played cards that cared about the graveyard order (Death Spark, anyone?), which is why they haven't been printed in more than a decade, and tournaments that do not include those cards are basically free to ignore this rule.
- Regeneration was considered this for quite some time, including by the developers themselves. While it was relatively straightforward in the early days of Magic and the concept was simple - pay a cost and have a dying creature brought back to life - increasing complexity of the rules led to plenty of confusion as to how it was supposed to work. It's been grandfathered in and clarified since, but Word of God has said that a rule like Regeneration never would have made it off the drawing board if it were thought up today. New cards no longer use it at all - instead, cards wanting this type of effect become "indestructible until end of turn".
- The Protection keyword ability has also historically been a source of some confusion, as it is shorthand for several distinct abilities (for something that has protection from a given category: all damage is reduced to zero, it cannot be targeted by a spell or ability, it cannot be blocked, and it cannot be enchanted or equipped). Newcomers to the game often find the mechanic confusing because it is non-discriminatory (something with Protection from Red grants protection from ALL red sources, including friendly and/or beneficial ones), and it has several notable omissions (it does not prevent "Destroy" effects, global effects, effects that produce counters, or effects that target the controlling player and force THEM to do something to the protected card). Worse, it still shows up fairly regularly, and several powerful cards have significant Protection abilities (Emrakul has Protection from All Colored Spells, while Progenitus has Protection from Everything), making those distinctions fairly important.
- Summoning conditions in Yu-Gi-Oh! in regards to reviving monsters. If a monster's effect says it can only be special summoned one way, can it be special summoned from the graveyard after being special summoned through that method? For some cards (Dark Necrofear,most ritual monsters, most fusion monsters), yes. For others (Armed Dragon LVs 7 and 10, Rainbow Dragon, most Elemental Hero fusions), no. The only way to distinguish between the two is whether the card reads "can" or "cannot... except..." while the rest of the Summon condition text is nearly identical. While the text formatting for modern cards makes the difference more distinctnote , old cards that have yet to receive a reprint in this format are still subject to this problem.
- Ever since Soul the Duelist was released, some cards had the text that said "ignore summoning conditions." This is clearly self explanatory when special summoning from the hand or deck so most likely, the logic for most players at time was that if it applied to reviving it after using a Foolish Burial, then the same situation could occur right? WRONG! According to Konami's official ruling ever since the release of Level Modulation in Elemental Energy, a monster with a special summoning condition, whether it can be revived or not by other card effects must always be summoned properly first before it can be revived, thereby the "ignore summoning condition" clause not applying in this situation. So a monster like Armed Dragon LV7 must be special summoned to the field first if players want to revive it with Level Modulation. The fact that there is an exception to this rule is not implied on the card text, which makes the game look inconsistent.
- The fine print on spell/trap/effect monster cards can also lead to some unusual circumstances and headaches. Legendary Fisherman on the Field while "Umi" is active? If no other monsters are on the field, opponent can attack your life points directly. Trap Card negating the effects of all monsters on the field? Monsters can still be special-summoned by their own effect, ignoring any change to ATK and DEF as a resultnote . Both of these are official rulings. Also, flip effects of monsters ONLY activate after damage calculation. A face-down defense-position monster that is attacked is NOT flip-summoned, it is merely "flipped". A handful of cards have the exact text "When this card is flip summoned..."
- There are cards (such as Thunder King Rai-Oh that specify that they can negate the special summon (any summon that isn't a normal summon or flip summon) of a monster. Despite what they say, they can only negate certain special summon; they can negate anything where a monster special summons itself without starting a chain (synchro summon, xyz summon, Cyber Dragon, Black Luster Soldier - Envoy of the Beginning, etc.), but they can't negate a special summon performed during the resolution of another card's effect (fusion summon, ritual summon, Monster Reborn, etc.). This is because you aren't allowed to activate effects during the resolution of other effects. Cards that can negate any special summon have to explicitly say that they can negate a special summon or an effect that would summon a monster.
- The missing the timing rule. There are four types of effects that activate when a certain condition is met (they take the form of "If X, Y", "If X, you can Y", "When X, Y", and "When X, you can Y"). An "If" effect occurs as long as its condition is met, and is incapable of missing the timing. A "When X, Y" effect must occurs right after its condition is met, but can't miss the timing because it's mandatory. "When... you can" effects, however, MUST happen immediately after their condition occurs; since it's not mandatory, and thus doesn't HAVE to happen, it won't happen if anything else happens in between when its condition is met and you're allowed to activate new effects. This means that if its condition is met during any link of a chain other than the first link, or if its condition is met during any part other than the last one of the resolution of a multiple-part effect, it'll miss the timing because the rest of the chain/the effect it was met during happens before you have a chance to activate it, and thus the condition is no longer correct by the time you're able to activate it. For example, if an effect can activate when a monster (let's call it monster A) is summoned by another monster's effect, but that monster is summoned during chain link 2, then you won't be able to activate it after the chain ends because link 1 happened during the small window of opportunity when you were allowed to activate the effect, forcing you to skip it. Similarly, if you activate a monster's effect that allows you to summon monster A, then do something else (such as tributing another monster), then the second half of the effect will cause you to skip past the window of opportunity, again forcing you to skip the activation of monster A's effect. Confused yet?
- Unfortunately, this rule was introduced to avoid game breaking infinite looping combos. Now this issue could have easily been averted if cards for given a once per turn restriction, but Konami did not really think much of it until later. The other alternative would be to ban and the most controversial solution is to edit the cards that cause this problem.
- Star Wars Customizable Card Game: "Attrition". For a vastly simplified explanation, at the end of most larger battles, both sides are assessed a penalty, in addition to the penalty paid for losing a battle, which can only be paid by discarding combatants (as opposed to discarding from one's hand or deck), which counts simultaneously toward the penalties paid by the loser; this penalty or its remainder is often waived if the characters remaining have sufficient Plot Armor, but how much plot armor is needed depends on the whole penalty, regardless of how many has to be paid by Red Shirts, and the loser's penalty remains if it's not paid by the time remaining attrition is waived, and can, if the player wishes, be paid by discarding these characters. Even in a game notorious for Loads and Loads of Rules, the complications that would crop up around this one in particular are legendary.
- Dungeons & Dragons:
- Before 4th edition, initiating a grappling attack was usually cause for your entire gaming group to throw large, heavy objects at you. There's a reason the trope is called Grappling with Grappling Rules.
- Subduing dragons in early editions required the GM to recalculate what percentage of the dragon's HP you had burned through with non-lethal damage and then make percentile rolls. Worse, it basically amounted to giving a rampaging, roaring engine of death a blanket party and hoping it decided to cry.
- Attacks of Opportunity/Opportunity Attacks started out like this in Third Edition, so each successive edition of the game has mostly scaled them back. The basic principle behind them was simple and understandable: In a game that uses turns for simplicity instead of real-time, there should be some kind of restriction against a character abusing the turn-based rules to simply bypass a whole group of defenders to take out a weaker target, steal an object, etc. The problems occurred with both confusing terminology and an "everything but the kitchen sink" approach as more situations were added to what could trigger an Opportunity Attack. The former described this as a situation where the trigger creature lowers their defenses, but a more accurate description would be a situation where the trigger creature lowers their counter-attack offense: i.e., you can take a free swing at them because you're not worried about leaving an opening for them to swing back at you. The latter issue combines with the first issue confusion to where using an action triggers an attack even though the condition where the action was made isn't changing regardless of the action. To explain, why does attempting to stand up from prone trigger a free attack but simply lying helplessly prone does not, or attacking someone without a melee weapon in hand (e.g., crossbow or punching) triggers an Ao O but simply standing there unarmed doesn't? *** Fourth Edition reduced the circumstances to just attempting to move past a creature or use a ranged attack next to them, although oddly giving the defender supposedly unlimited attacks as long as it was against a new target, and Fifth Edition reduced this even further to just moving past the defending creature completely, as you can still circle around an opponent. No edition has brought up the concept of removing your ability to use Ao O if other enemies are engaging you (e.g. if you have five creatures engaging you, how can you possibly get a free swing at a different one?), but most likely is due to the rules getting just too complex at that point.
- The 3rd edition of Nobilis introduced a system for resolving non-miraculous actions by mortals that is a bit confusing because it focuses not on immediate success or failure but the effect that taking such an action has on your life. (e.g. Achieving long-running goals, impressing people, making your life better, doing "the right thing" etc.) Handling task resolution at this level is hard to wrap your head around, but it's mitigated by the fact that most mortals don't have the "oomph" to regularly get really high on the scale. Normally. However, Nobles can do so trivially with Aspect miracles, and the "Shine" trait gives an extra push up the chart for mortals doing something a Noble tells them to do.
- Draws are exceedingly rare in Shōgi, Japanese chess. However, they can occur under the right circumstances where both players are able to surround their king with promoted pieces. In this case, the winner is decided by counting all of the pieces owned by each side, with a point value for each (5 points each for bishop and rook, one point for all others). If both players have at least 24 points, it is a draw. If not, the player with more points wins.
- Diplomacy is normally a relatively simple game - there are four basic moves and rules for resolving their interactions - except that convoys, where an army moves between locations using a chain of naval units possibly owned by another player, are notorious for creating problems. This began with the discovery that a player could convoy another player's army without their knowledge or consent, and continued into situations creating actual paradoxes. For example, an army which travels via a convoy to displace another army which is cutting the support of a fleet which is attacking the same convoy; if the convoy succeeds, the support is not cut and the convoy defeated, so it ought to fail; but if the convoy fails, the support is cut and the convoy survives, so it ought to succeed. The tournament rule book at one point simply abandoned any attempt at making sense and spent several pages presenting a humanized version of the source code of the automated resolution system.
- In tournament and club play, there are procedures for dealing with a board that cannot be scored for any reason at one or more tables. These are mathematically complex, and can result in a pair not involved having its score reduced - for example, a pair that might otherwise have gotten 10 out of 10 on that board will now get only 9.9. This is disliked both by new players (who don't understand the calculations involved) and by experts (for whom that small adjustment can have an impact on their placement).
- The scoring procedures for a fouled board (where cards got moved between hands somehow, so that not everyone played exactly the same hand) are even more complicated; fortunately, this comes up very rarely.
- The rules for a revoke (playing a card of a suit other than the first suit led when following suit is possible) are a bit baroque and have resulted in numerous appeals at clubs and events. The rules state that up to two penalty tricks may be awarded to the aggrieved side - one for the trick where the revoke happened, and one for the trick when the revoke card (the one that should have been played on the revoke trick) finally gets played. However, this is only supposed to apply when both the aggrieved partnership lost both tricks in question and it's deemed that they would have won the tricks in question if play had progressed properly (for example, if the aggrieved side would have won the revoke trick regardless, they wouldn't be eligible to receive a penalty trick for that trick). Arguments about how play would have progressed differently can result in much hair-splitting over penalty tricks rewarded, and that's even before getting into the issue of how many people (including directors, at clubs and tournaments) argue that there should be a two-trick penalty regardless. Some players will just Hand Wave the two-trick penalty rule as being hard-and-fast just due to not wanting to deal with hashing out how things should have gone.
- Brass has the Liverpool-Birkenhead virtual link. It allows a player who has a presence in either Liverpool or Birkenhead to build in the other location using industry cards instead of city cards. While the intent was to make it harder to lock players out of the Port spaces in Liverpool or the Shipyard spaces in both cities it ended up confusing a lot of players. The game's creator later changed the rule so that the virtual link could only be used to build a Shipyard in Birkenhead and in the latest reprint the virtual link was removed entirely since it was generally considered superfluous.
- The Calvin Johnson rule, which states a ball cannot be considered a catch if the receiver loses control of the ball going to the ground. Since the 2014-2015 playoffs, it became unclear among the general public on what a catch is, which led to fans saying, "What is a catch?"
- The "targeting" rule recently added in college football. If a defensive player hits an offensive player in the head or neck area and is deemed to have been "targeting" a player (i.e. having intended to hit him in the head or neck area), a 15-yard penalty is assessed, and the player is ejected from the game (and suspended for the first half of his next game if the infraction occurred in the 2nd half). One problem is that this call is always reviewed, and if overturned, doesn't involve any penalty at all, even if the hit was still clearly unnecessary roughness. Then there are the borderline hits where a player was launching himself at another player's midsection, but that player ducked or dove and got hit in the head instead.
- One example by obscurity is the "Fair Catch Kick". A team receiving a kickoff can call a fair catch and immediately try a free kick-style field goal from the spot of the fair catch. To say the rule is rarely utilized is an understatement: It's only been used 24 times (that we know of) in the NFL, and was last used successfully in 1976.
- The offside rule. The rule is of course very straightforward (basically, if you were behind all the defendersnote when the ball was passed to you, the move is ruled illegal and the defending team gets a free kick); it's just tediously worded and has a reputation for being so complicated that newcomers declare themselves confused without even trying to understand, and those who understand it feel the need to explain it in as complicated and detailed a way as possible. This in turn gets people annoyed. The complications and special circumstances that move it into The One Rule territory are:
- You can't score if you're behind all the defenders but one, with the goalkeeper counting as a defender. This only matters when the play has gone past the defending goalie, but there's another defender between the player who got the ball and the goal. Which is to say, hardly ever.
- If you were behind the ball when it was passed to you, you're onside regardless of where any defender was.
- The same is true if you were in your own half of the field when it was passed to you.
- Every offensive player is onside during a corner kick, goal kick, or throw-in until the ball is first touched by a player.
- Sometimes, an offside player doesn't even need to touch the ball in order to be offside, which happens if he is interpreted as being involved in the play in some way (like letting the ball pass through his legs or blocking the field of vision of the goalie).
- The rule isn't just difficult to explain, but even more difficult to enforce. To call someone offside an official must keep track of the position of the ball, the position of the defending player(s) and the position of the attacking player(s), all of whom are in motion. In close situations offside calls are essentially arbitrary and without any ability to use video review on calls the offside rule in Soccer essentially becomes a Rule Zero that officials can use to put their own stamp on the game.
- However, in major league games, there are two line referees, who move along the side lines of the field, always at a position where they can accurately detect an offside. Communication with the main referee is performed via wireless headset nowadays. (They are also responsible for reporting when the ball leaves the field, and they can also report fouls.)
- The the offside rule in Association Football can be considered an artifact from the older Football codes it evolved from where there exists a well defined line of scrimmage. The problem came with attempting to adapt the same concept to a free flowing sport with no stoppage of play. The more common solution is to use fixed "zone" based offside system.
Examples of the Offside Rule within works
- The inability of anyone to explain the offside rule is parodied in The Little Book of Mornington Crescent. The explanation of Mornington Crescent's offside rule is half a page of dense, jargon-filled gobbledegook. Which concludes "This should not be confused with the offside rule".
- The Brazilian championship of soccer had the tradition of always changing the formula. Sometimes yearly (and if a big team was meant to be relegated, there would be an Obvious Rule Patch to keep it in the top level). In 1999, the relegation was similar to an Argentine rule, based on the average points between 1998 and 1999. But it got worse when a team who suffered a last-minute downgrade started a lawsuit...
- The first "Mr Blobby" based "Gotcha Oscar" on Noels House Party (a Candid Camera Prank based around a fake [and entirely unworkable] kids' TV show, thereby removing the need to hide the cameras) was footballer Garth Crooks trying to teach Mr Blobby how to play The Beautiful Game, including an increasingly confused explanation of the offside rule. Some time later, an entirely unrelated skit about the Crinkly Bottom football team would claim that Mr Blobby was their coach, and still didn't understand it.
- The advantage rule, which is also used in soccer. (Ice hockey also has a similar rule called the "delayed penalty".) The officials are given the ability to wave off a foul if the team that was fouled would be in a more advantageous position if the foul isn't given — in footy, you'll often hear the announcers call "play on" when advantage is paid. Of course, because the rule is a matter of high-speed interpretation, fans on both sides of an advantage call will often be puzzled — if not downright angry — about the call. The loudest yelps will be given if the team that played on immediately loses the ball after the advantage call, as their fans now believe they were victimized instead of helped. It's far less controversial in soccer and ice hockey because in those sports, change of possession is far more common and expected. What's more, in soccer, the team that was fouled gets the ball for a free kick; ice hockey gets a faceoff instead, and the team that fouled has one less player on the ice, so in both of those sports the advantage rule rarely benefits the opponents.
- The infield fly rule. This rule is simpler than its reputation — an infielder can't deliberately let a fly ball drop in order to get an easy double play by picking off runners who would otherwise be forced to advance.note If there are runners on first and second base or the bases are loaded, there are less than two outs, and the umpire feels the ball would be caught with "ordinary" effort by an infielder, the batter-runner is automatically out and all force outs are negatednote . The reason why the rule requires a runner on both first and second (or bases loaded) is that, if there were just a runner on first, because the batter is running to first as soon as he puts the ball in play (assuming he didn't just give up in disgust), it is assumed that he would beat out any double play attempt if an unscrupulous fielder tried to get them bothnote . Whether or not the fielder catches the fly ball, the net result is the same: one more out and a runner on first. It is possible that the team on defense would prefer to have one over the other be called out (i.e., one of them is a better base-stealer), but such strategic use of outs is outside the umpire's concern.
- The balk rule. Balks are simple to explain, but hard to actually call. A pitcher has balked when he makes a motion towards a base, but throws to a different base. So a pitcher can't act like he's throwing a pitch and then throw to first base to pick off a runner, which is why when trying to pick off a runner, the pitcher will almost always move their front leg towards the base. The problem is, how do you classify a "motion"? Is it when the pitcher starts his windup? When he lifts his leg? When he moves his arm? There's also the issue of what counts as "towards" a base- if a pitcher starts moving in a direction between home plate and first base, for instance, which base is he throwing to? Balks are almost always controversial at the Major League level. Balks can also be called for similarly deceptive moves by the catcher. And there's some other things that count as balks, too- it's also a balk if the pitcher motions towards a base like he's going to throw but doesn't throw, if he starts making a throw without first fully coming to a "set" position, if he throws to home plate while his foot isn't on the pitching rubber, or, well, a lot of other things. There's even a few ways to balk that are clearly completely unintentional, like tripping and falling off the mound or dropping the ball.
- The NBA once had a technical foul for "illegal defense". Zone defenses were disallowed, since it allowed centers to simply camp under the basket. After a few years without this rule, they decided to make a rule that disallowed defensive players to be in the key (the painted area directly underneath and in front of the basket) for more than 3 seconds... which matched up nicely with the same rule for offensive players.
- The Duckworth-Lewis Method was devised as a totally fair way to decide matches affected by rain. Unfortunately it's an extremely complex mathematical formula the results of which change every time a ball is bowled, a run is scored, basically every time anything at all happens. Since its introduction, matches (one of them famously a World Cup semifinal) have been decided by one team's players and/or coach misinterpreting the results table and settling for fewer runs than they in fact needed. There are those, of course, who argue that the whole of cricket is in fact a case of Loads and Loads of Rules and it's difficult to deny... but Duckworth-Lewis is infamous even among those who understand everything else perfectly.
- The LBW (Leg Before Wicket) rule: "A batsman is out if he is hit by a legal delivery, which is not pitched outside the line of leg-stump, has not hit the bat and is going on to hit the stumps. If it strikes the batsman outside the line of off-stump he is not-out PROVIDED he was playing a shot at the time." Simple, no? ...No, not in practice. Recent use of infrared and computerised video replays to follow the line and trajectory of the ball has made it much easier for spectators to see if the decision is in fact out. note
Examples of LBW within works:
- In Stephen Baxter's Time's Eye, British soldiers from colonial-era India try to explain cricket to the army of Alexander the Great. They manage to get most of it across with gestures and broken Greek. They give up trying to explain Leg Before Wicket.
- In SF Debris' review of the Star Trek: Voyager episode "Persistence of Vision", a vision of his disapproving father asks Tom Paris several difficult trivia questions, which Tom successfully answers, until he asks him to explain the Leg Before Wicket rule, which Tom fails to do, causing the vision to dismiss him as useless.
- "Right-Of-Way": Another of those rules that are simple to explain, but complex to deal with. Simply put, you cannot attack into an existing attack, at least, not if you want the point. You must stop the incoming attack or remove the threat, then you can counter-attack. It's far, far more complicated in practice, involving as it does questions like "What constitutes an existing attack?", "What constitutes "stopping the existing attack"?" "What qualifies as "removing the threat"?" and "What the hell just happened, it was all so fast..."
Examples of Right-of-Way within works:
- In Robert Asprin's Phule's Company, during the fencing match between the Red Eagles and the Omega Company, Phule gives a brief explanation of right-of-way to the audience prior to the beginning of the match. They are okay with it during the foil bout. confused and angry about it during the sabre bout because the Omega Company fencer loses points to it all the time (he's not a fencer at all, but an escrima fighter, and he's clearly landing attacks that would work in a real fight, but violate right-of-way), and when he announces the epee bout, they cheer when he tells them that epee doesn't use right-of-way at all.
- Stop hits and time hits in fencing are in theory incredibly simple, as they are counterattacks which obtain priority over the initial attack (Thus escaping falling afoul of right-of-way) because the initial attack is too "long-winded" and so it was interrupted. For example, if A's attack is legal, but consists of four movements, B can stop hit A by counterattacking during that fancy, silly wind-up. Good luck with getting fencers and judges to agree on what is a stop-hit and what doesn't count in the heat of swift-moving competition.
- Buffalo Sabres fans are the only hockey fans that know the rules on players in the goal crease, the result of Brett Hull scoring a controversial Cup-winning goal off his own rebound in the third overtime period of Game 6 of the Stanley Cup finals. Video replay showed that Hull's skate was in the crease (i.e. the area in front of the goal, reserved for the goalie), which the Sabres argued was a violation of a rule then in effect that disallowed goals if an offensive player was in the goal crease. However, the rule stated that a player can enter the crease, as long as he has control of the puck, and the refs ruled that since Brett's shot rebounded to him, he had never lost control of the puck. After that disaster, the rules were changed, so that the player could now be in the goal crease, as long as they do not touch the goaltender. This led to some angry goaltenders as opposed to some angry Sabres fans.
- The NHL has a few rules that vie for the title. The consensus champion, though, is the "puck-over-the-glass" rule. Specifically, following the 2005 lockout, the NHL made it an offence to shoot the puck over the glass from the team's defensive end, netting the offending player a two-minute penalty for delay of game. It's suspected the rule was implemented to boost scoring by boosting penalty minutes (since teams on the powerplay score more), but it does so by penalizing something that is usually an accidental action and which causes no more of a delay than icing the puck (which is not a penalty). Few things are more frustrating than watching your team take one of these penalties (even worse, because icing is legal while on the penalty kill and many players try to bank the glass off the puck and out, this penalty usually gets called on teams already down a man, leading to a 5-on-3 penalty).
- Icings are easy to spot and deal with. Conversely, icings are hard as hell to accurately explain (at least until the rule was changed). Then there's "Hybrid icing". Intended to reduce injuries, it says if a defender is closer to the puck than any member of the opposing team at the faceoff circle, icing is called immediately. Problems arise when you consider that a forward and defenseman will almost always be skating towards the puck at different angles, making it difficult to properly assess who's closer to the puck and leading to controversial calls. There's also the fact that a fast forward could still beat out a defender at that point, resulting in offensive opportunities being lost.
- "No forward passes" is an integral part of both codes of rugby, but casual fans - and even some long-time fans and commentators - have been confused by passes that travel forward, but are ruled as "flat" or "backward". This is because the laws take into account the effect of the player running forward while releasing the ball (sometimes called "the Momentum Rule"). Even if the ball is caught further forward from where it was released, the pass isn't forward as long as the player doesn't propel the ball forward. This misunderstanding is common enough that World Rugby, the governing body for rugby union, released a video clarifying the issue.
- In World of Warcraft the armor penetration stat ended up so confusing and defining some classes to such a degree that in the Cataclysm expansion, it was removed from the game entirely. Armor penetration was of course distinct from but interacted with abilities that reduce enemy armor, abilities that bypass enemy armor, and amount of enemy armor. And you needed to calculate all this to know with what gear and on which fight armor penetration became better than attack power (though by the end of the expansion it became stack armor penetration, always).
- Early games in the Super Robot Wars franchise included a stat called "Limit". Intended as a nod to Mobile Suit Gundamnote , Limit would throttle a character's Accuracy and Evasion if they were too high for the machine they were using, forcing the player to spend extra upgrade money just to make machines perform as they're supposed to. Limit lasted all the way up to the original Super Robot Wars Alpha before quietly disappearing, with absolutely nobody mourning the loss.
- Baten Kaitos had the Turn Timer. As you class up in the game (meaning you could hold more cards in your hand) a timer was introduced where if you didn't complete your turn in time, you'd forfeit it. It starts at 30 seconds but by end game you have only seven seconds to look at your cards and decide on a move. Unsurprisingly this was replaced with a better system in the sequel.