Here are some facts I collected from a range of sources a long while ago.
Here is a list of random fact about Runescape. They are in no particular order.
1. When you equip The Elemental Shield it "matter-materializes", yet when unequipped it dose nothing.
2. When cooking a full load of lobsters, your weight decreases by 2kg by the time you've finished.
3. You get sap from evergreen trees, but not maple ones. Have you ever heard of evergreen syrup?
4. When you die with 3 Bronze Daggers and 3 Christmas Crackers, you keep the 3 Bronze Daggers.
5. Eating a lobster will only take 2 Seconds.
6. An aggressive monster will stop being aggressive after you are more than twice its level.
7. When you shoot arrows, they disappear 20% of the time.
8. When Running you go ten squares in one second.
9. When Walking you go four squares in one second.
10. After being in a monsters territory and killing them for a certain amount of time, they will no longer be aggressive.
11. The first option for pineapples and watermelons is eat but you can't.
12. When lighting fire, you always move one square to the west.
13. The Statue at the fork north of Falador looks the same as the Statue of Baxtorian from the Waterfall Quest.
14. The Initiate plate is called a platemail while every other plate is called a platebody.
15. Weapons up to rune have a solid gold handle while dragon weapons have a grey, stone handle.
16. There is a picture of the Silverlight on the Anti-Dragonfire shield.
17. When searching bails of hay or piles of hay, it is possible to find a needle.
18. Guards that can't be attacked wield halberds, while guards that can wield swords.
19. Arrows always hit the person in the heart, no matter where the arrow was aimed.
20. When smithing, the armour that you make weighs more than the bars you used to make it.
21. All random event whirlpools swirl counter-clockwise.
22. The bone spear is like a halberd, yet you can wield a shield with it.
23. When an object or NPC is directly NE, NW, SW or SE it will say, "I can't reach that."
24. Bows and Granite Mauls are held in the wrong hand.
25. When wielding a P2P weapon in a F2P world you can punch or kick with it.
26. Pumpkins heal 14hp.
27. On many skills the animation goes faster than the text.
28. Darts are the fastest weapon in the game.
29. You don't have eyes, they are black lines.
30. If you die with a skirt and legs, you keep the skirt.
31. Low alching only have 1 gold poof thing, high alching have 3.
32. When you high alch while your cannon is spinning, it stops spinning until you finish alching.
33. When you log in you are always looking south.
34. When you eat an onion it says, "It's always sad to see a grown man/woman cry."
35. When an object or NPC is directly NE, NW, SW or SE it will say, "I can't reach that."
36. You can find a Cycolpse at Ardougn Zoo and in the Warriors Guild
37. When you try to high alch coins, it says that coins are already made of gold. Yet, when you high alch gold bars it doesn't.
38. When using a sextant in the Air Runecrafting alter, you will find that the altar is in level 56 wilderness.
39. Player animation are done one body part at a time.
40. The exp which would be needed for level 100 is exactly 14,391,160.
41. Burthrope stairs going down to the game room are backwards.
42. You are allowed to bring a bazooka and a knife onto entrena, but you are strictly forbidden from bringing a glove.
43. When your character talks in a text box, his/her head moves from side to side a bit.
44. Super strong poison only does up to a 6 from poison.
45. Your character complains a lot during member quests.
46. You can trade Gabooty while wearing a mask, but you can't talk to him normally.
47. Chickens cannot kill you, no matter what
48. A dragon chain alchs for 150k!
49. After you talk to a NPC he always turns to face you until someone else interacts with him
50. If you stand near a sheep and it baas, you can hear it
51. A farm near arrack has sheep that are always sheared.
52. Of the three monsters in the Smokey well, only 1 auto-attacks you (fire giants)
53. Only 1 of the slayer monsters auto-attacks you, Aberrant Spectres
54. Infernal Mages drop 2 different pieces of Mystic Robe.
55. You cannot take a cannon into the slayer dungeon or tower because of "dark forces"
56. You get "tired" from taking the Shilo Village-Brimhaven cart ride.
57. Falling off Baxtorian Falls does 8 damage.
58. Examine the rope you tie to the rock when going to the waterfall. It says "Rope" with no period.
59. The Dragon scimitar special attack, if it works, still prevents the target from using protect prayers even if they weren't when the special occurred.
60. In the south Ardounge bank, you can bank at the closed booth by selecting "bank" banker. This works at many other banks too.
61. If you are fighting a team or many monsters, and you are standing in non-multi combat while your opponents are in multi combat, you can still be attacked by all of them.
62. You cannot set up Castlewars barricades in the doorways of the side doors, but you can set one up on either side of that square for the same effect.
63. You cannot set a barricade right outside the energy barrier in castlewars, but you can set one right inside.
64. If you die in the castle wars waiting room, you just respawn in a different place in the waiting room.
65. You can only set up a barricade in the waiting room with 5 or less minutes until the next game.
66. You can't post more than 10 times in 5 minutes on the forums.
67. Cabbages picked from draynor manor "taste slightly better than normal" and boost your defence by one level temporarily.
68. Looking through a sextant, the position is random every time. It doesn't follow a set pattern.
68. When preaching from prayer books, other players cannot see your preaching in the chat box.
70. When private messaging a player mod, when you are receiving a message there is a silver crown, though when you send a message there isn't one there.
71. Jagex's default drop table for a monster is bones 100% of the time and no other drops. By default, the monster is also non aggressive.
72. If you die and have a freeze condition, you are still frozen for a few seconds.
73. If you die and lose some hp or skill levels due to poison or a disease at the exact same second, you still lose the hp or stats.
74. If you gain experience and are in the high scores, your name on the high scores doesn't get updated until you log out.
75. If you are in castle wars by your teammates and you die when you have retribution on, you explode like normally. However, only enemies get hit by the explosion. But you still try to hit your teammate, as it says "Saradomin/Zamorak won't let you attack you
76. You cannot telegrab an item if you are standing on the wall by the lobby in castle wars if the item is actually in castle wars.
77. There are 3 audience members in the mime theatre, and they are said to be Saradomin, Zamorak, and Guthix (this seems possible, as they are wearing the right colours, and nobody knows how to get to the mime theatre besides the mysterious man, and the mime)
78. When you examine a maple tree it says I bet this will make good syrup.-If someone closes the do before while you walk through it you walk through the solid door.
79. There are only 3 bankers with names in Runescape. The one in Burg de Rott and the one in the Warriors Guild and Emerald Benedict. All of the others are simply called Banker.
80. There not a single proper toilet in RUNESCAPE. Only baths.
81. If you examine normal gloves it says These will keep my hands warm but ice gloves say these will keep my hands cold.
82. Most/npcs that you can interact with have their name in yellow text.
83. Dragon halberds have a red point at the end opposite the blade; regular halberds don't have a point at all.
84. You can swim in a river (due to a failed agility obstacle) with metal armour without trouble.
85. Black Demons stand exactly 2 times as tall as a player's character.
86. Barrows brothers have Legend capes.
87. You can not stop yourself from smithing when you start smithing 5 or 10.
88. In the quest Wanted! your character says, "Dude."
89. The Edgeville dungeon slayer master has Steel Plate legs, a Steel Two-Hander and Dragon Square.
90. You don't have any fingers.
91. Many two handed weapons when using stab will be used in one hand.
92. The Duelling Arena hospital room doesn't have any glass in the window.
93. There are 82 Cabbages in the Lumbridge Cabbage Field.
94. When using a sextant, when you move square-by-square, each square are intervals of 2 minutes.
95. You can climb down broken ladders in the Dark Knights' Fortress, but not up.
96. Ice warriors change colour when they attack.
97. Dragon Square high alchs for 180k, but, the Dragon Chain only alchs for only 150k.
98. At Barrows, you can go to the chest and get a reward without killing any monsters.
99. If you high alch while being attacked the damage doesn't show until after alching.
100. The gate in to The Legends Guild is made out of pure Mithril.
101. When you attack female villagers of Canifis without Wolfsbane, when they transform into a werewolf, their skirts change into pants.
102. When you fill a druid pouch, the most powerful "nature's harvests" get placed in it first.
103.
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104. The Sinclair mansion in Seer's is smaller then the "Mansion" in Falador.
105. The Duel Arena alone, is larger then the Tree Gnome Village with its maze.
106.
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107. The Biggest House is Draynor Manor.
108. Mos Le' Harmless Island is the Farthest East, Ape Atoll South, Tyras Camp and Prifddinas West, and Wild Agility Training Area and Axe Hut North.
109. There are no Mining SHOPS above ground.
110.
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111. When cooking a full load of lobsters, your weight decreases by 2kg by the time you've finished.
112.
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113. The Lighthouse would actually be an island if it wasn't for the bridge and jump-y rocks.
114. If you don't do anything, the time before you log out is 1 min 29 sec.
115. Fastest time you will get fish is one per 2 seconds.
116. If you follow someone, then teleport out, your character still follows it.
117. You can't die in Tutorial Island.
118. If you have a poison/disease and you will switch worlds to a F2P world, the poison/disease will still take effect.
119. There are 3 ruins in Wilderness.
120. If you walk five steps north, eleven steps west, and thirteen steps north from the Draynor Village bank first booth, you will find a dock leaf plant.
121. Every items' top is facing north when dropped.
122. If you cut down a tree it looks like you are cutting it from top to bottom.
123. When you talk to an NPC his/her face is always on the left and yours is always on the right.
124. We roast lobs in RS, but in real life we boil them.
125. One of the people in the tavern in Arrack knows that Runescape is a computer game.
126. When you low alch it gives you the same amount of money as the general store would for that item.
127. The examine in Yanille sand pit is different from other ones.
128 There are 9 fountains inside and around Camelot castle.
129. There are only 10 magic trees in Runescape.
130. 22 islands surround the lighthouse.
131. You can die taking beehives in Catherby without insect repellent.
132. There's no electricity in Runescape.
133. Every castle/mansion involves a quest.
134. There are 7 dyes in Runescape.
135. Apples on apple trees grow back
136. You can get to level 5 on tutorial island
137. There are 36 Emotes
138. A lava eel (from heroes quest) can live inside hot lava but can be cooked on a fire.
139.
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140. There are only 3 Cities with the word "Port" in it's name.
141. The Duel Arena alone, is larger then the Tree Gnome Village with its maze.
142. The Biggest House is Draynor Manor.
143. Post Phasmatys is the Farthest East, Void Knight Island South, Tyras Camp and Prifddinas West, and Wild Agility Training Area and Axe Hut North.
144. There is Only One, Amulet, Staff, Paltelegs, Shield, Jewellery, Candle, Apothecary, Mace, Skirt, Chainmail, Silver, and Spice Shop that are above ground.
145.
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146. RUNESCAPE can also be RUN! ESCAPE!
147. When You light more than 1 fire, they won't always go out in the same order.
If you have any to add, please add it here!