Complicator

By touching any creature anywhere and casting this spell, the target receives 1 (or 2) "spell-conditions" on all spells of a certain level (determined by 1d4 initially), if the target fails a Constitution saving throw (DC-10 + spellcasting modifier). It now has to fulfill/meet the additional condition(s) added, before casting any of the affected spells.  If the CON save was a critical failure, the number spell-conditions doubles. If a spells condition(s) has already been satisfied once, additional casting of spells of the same level is possible with no further penalties. Roll a d100 for the "conditon" that the affected spells have to fulfill before casting. The list of conditions can be found at the bottom of the description. The creature whose spells have been affected instinctively knows what spell-conditions it has received.

At level 5:

Roll 1d4 for the level of the spells you are trying to restrict. On a failed CON save from your target, roll 1d100 (or 2d100 on a critical failure) to see which condition applies.

At level 7: 

Roll 1d6 for the level of the spells you are trying to restrict. On a failed CON save from your target, roll 1d100 (or 2d100 on a critical failure) to see which condition applies.

At level 9:

You can choose if you want to roll 1d8 and try your luck in restricting higher level spells or if you want to roll 2d4 and add restrictions to 2 lower spell levels. If both d4 rolls are the same, roll 2d100 (or 4d100) for that spell level only.

(Note that further spell conditions can be added to this spell in editions where spells beyond level 9 exist. In that case you can decide for yourself how you want this spell to work out. How you change it up, if you want your own spin on it, is up to you. Also, feel free to comment feedback.)

Spell-condition d100 table:

"To cast this spell you must also..."

1. eat a handful of dirt
2. imitate the native language(s) of your target(s)
3. use your shoe as your arcane focus
4. laugh hysterically
5. kiss the ground
6. admire your reflection
7. sacrifice half of your current hit-points
8. pray to a deity you don't believe in
9. look like the opposite of your current gender
10. fart while casting
11. walk 10 ft. north
12. do 5 squats while casting
13. be poisoned
14. take off one of your clothes
15. hang upside down
16. punch whatever is closest to you except air
17. be in the air
18. look at your own nose
19. drink a harmful liquid
20. walk 10 ft. south
21. be within 500 ft. of a village or settlement
22. know your targets full name
23. show your target(s) your middle finger
24. have 5 or less hit-points
25. hold a stick in your hand
26. kick your nearest ally
27. lie flat on the ground
28. scare away a nearby animal
29. have at least 4 creatures of different races near you
30. play any instrument
31. lean against a tree
32. imitate an unintelligent creature
33. walk 10 ft. east
34. be invisible
35. wear 5 rings
36. spit on the ground
37. throw a fish at your target(s)
38. spread apart your arms in a T-Pose
39. be in the vicinity of a body of water
40. sprinkle glitter into your eyes
41. be underground
42. be on fire
43. insult the deity you believe in
44. have at least 3 magical items on you
45. stand on one leg
46. walk 10 ft. west
47. stand on an elevated platform at least 25 ft. above your target(s)
48. be on a transport vessel (a boat, a carriage, a horse etc.)
49. wear glasses
50. be near a creature that is at least 7 ft. tall
51. convince your target(s) you aren't real
52. pull out one of your finger nails
53. eat something sweet 
54. do a split
55. be around something dead
56. flirt with the nearest boulder
57. spit in your targets direction
58. be located behind your target(s)
59. be in broad daylight
60. be surrounded by mist of any kind
61. make your target laugh
62. try to hide behind a pebble
63. paint your right hand a different color
64. have a scar on your body
65. pull out your hair
66. run straight at your target(s)
67. possess this spell 
68. be near a dragon or draconic being
69. be standing in rain
70. pray to the god you believe in
71. look in the direction opposite your target(s)
72. cry
73. scream for help
74. ignore your target(s)
75. throw a handful of leaves at your target(s)
76. warn your target(s) of this spell beforehand
77. be around at least 2 creatures that aren't hostile towards you
78. drink your own blood
79. insult yourself
80. lift your own bodyweight 
81. pray to the god your target believes in
82. eat a mushroom
83. catch and hold a firefly
84. whisper the incantation into your targets ear (if the spell does not require an incantation whisper anything else)
85. throw a deck of cards into the air
86. pick up dust, sand or rock from the ground and blow it into the air
87. run as far away from your target as possible
88. cast a spell one level higher than this one before (does not apply to 9th level spells)
89. laugh at your own joke
90. break your targets concentration before casting (at any point during this combat)
91. have a knife, sword or similar weapon stuck in your body
92. target a flying creature
93. be terrified of something
94. start an evil monologue about what you want to achieve (even if it isn't evil at all)
95. make your target(s) think you are casting a different spell
96. perform a somersault
97. target the creature furthest away from you
98. write a slur in your mother tongue on a piece of paper and burn it 
99. eat a living rat
100. smear your face with honey, dust, and blood