The game is played with at least four players (in teams of two each) with the team with the player whose birthday is coming up next going first. Everyone starts out on a purple "Planet Cranium" spot, and the team in play draws a card from one of four boxes, each represented by a character and signifying a different set of skills:
- "Creative Cat": These cards employ artistic skills, having a player try to make their teammate guess what they're sculpting out of clay (provided with the game) or drawing (even drawing with their eyes closed).
- "Word Worm": These cards employ skills relating to words, as a player challenges their teammate to unscramble a word, spell it (or spell it backwards), fill in the blanks of a phrase, or define a word.
- "Data Head": These cards employ knowledge based skills, with players making their teammate answer trivia questions (that may or may not be multiple choice) or true or false questions.
- "Star Performer": These cards employ acting based skills, with players making their opponent guess what they are from impressions or charades, or make them guess what song they're humming.
If an activity is successfully completed before the sand in the timer runs out, the team gets to roll a 10-sided die and move to the space corresponding to the color that the die lands on before the next team takes their turn. If the activity is not successfully completed by that time, the next team just takes their turn. For extra competitiveness, there are two paths in the game — those who cleared their first challenge while on a Planet Cranium space get to use the shorter "fast track" while those who didn't use the longer "scenic path" When a player lands on a non Planet Cranium space, the color of it corresponds to the type of challenge they must do (blue for Creative Cat, yellow for Word Worm, red for Data Head, and green for Star Performer). However, whenever they come across a Planet Cranium space, they must stop on it, even if their roll would take them past it.
Additionally, certain cards are marked as "Club Cranium" (or "All-Play" in more recent versions). For these cards, all teams attempt the activity, and the first to shout out the answer wins a bonus roll, afterwards, the team who drew it take its regular turn. Additionally, Club Cranium/All-Play cards don't penalize you if you're on a Planet Cranium when you draw them — you can still try to get onto the fast track on your normal turn.
At the end of the game, the team reaches the "Cranium Circle," where they must complete one activity from each of the character boxes, starting with the one whose color they rolled when they got it (or any one if they rolled purple). Afterwards, they move to Cranium Central, where they must complete an activity of which the opposing team decides the box they draw from. If they can complete it, they've won the game.*
The artwork for the game is done by Gary Baseman, who would later go on to create Teacher's Pet.
The game has gone on to have many expansions, variations, and spinoffs all falling under the "Cranium" brand (owned by Hasbro since 2008) with a 25th anniversary edition that has new presentation by Prospero Hall. Any variations to the standard "Cranium" game will be covered under tropes relating to them.
Tropes present include:
- Awesome, but Impractical. The quickest way to get across the board is to keep rolling purple, thus landing on a Planet Cranium every time before going straight to the Cranium Circle. That said, the chances of it are slim- 1 in 15,625- and that's assuming you complete your first activity on a Planet Cranium every time. If not, rolling purple still allowed you to avoid the scenic path initially, but the more recent versions feature additional purple spaces on the scenic path.
- Color-Coded for Your Convenience. The non Planet Cranium spaces are colored to let you know which box to draw from on your next turn (blue for Creative Cat, yellow for Word Worm, red for Data Head, and green for Star Performer).
- Extra Turn: Regardless of which team completes the activity, drawing a Club Cranium/All-Play card will get the team who drew it another turn after it's played.
- Extrinsic Go-First Rule: The team with the player whose birthday is coming up next goes first.
- Literal Bookworm: One of the four main characters in the game is Word Worm, a bookish worm who wears glasses and a fez. His card challenges are word problems such as anagrams, spelling words backwards, and word definitions.
- Obvious Rule Patch: In early versions of the game, even if you did not successfully complete your first activity on a Planet Cranium, rolling purple when you finally completed one would still render the scenic path pointless and allow you to go straight to the next one. Later versions would change this so that an additional purple space would appear on the scenic path before the next Planet Cranium.
- Sdrawkcab Name: Word Worm cards that require someone to spell a word backwards are categorized as "Gnilleps."
- The Smurfette Principle: Star Performer the starfish is the only female character among her group.
