Objective of the Game

In Kelp, one player takes the role of the Shark, trying to hunt the Octopus, and the other takes the role of the Octopus, trying to survive. Both players have different goals and paths to victory.

The Octopus wins either by surviving until the Shark is exhausted, or by eating all four food blocks. The Shark has only one way to win: by successfully striking the Octopus and beating it in the final confrontation.

Anatomy of the Board
The board represents a Kelp forest and is divided into different zones.

• Zones The Exposed Zone is in the center. The Kelp Zones are adjacent to it. The Rocky Zones are in the corners of the board.
• Shark Den The Rocky Zones include the Shark Dens. On one of these Current spaces the Shark starts the game, and it may also be returned there because of certain in-game actions.
• Block Space Each zone has a space for the Octopus blocks.
• Zone Value Each zone has a value that represents the visibility in that part of the Kelp forest. The Exposed Zone has value 2+, the Kelp Zones 4+, and so on - a placed die must be equal to or greater than the zone value.
• Shark Movement Path The lines represent the path the Shark can follow when it moves.
• Current Space The blue squares represent Current spaces. The Shark moves on these spaces and can place Current dice on them.
• Food Track Food blocks are placed here whenever the Octopus eats them.
• Hunger Track Dice are placed here whenever the Shark uses stored Energy or strikes.
• Growth Track Formed by the 4 Growth tiles; grants the Shark permanent abilities.

Setup
This is automated on BGA, but for better understanding see as follows:
Fill the Shark dice bag with 7 blue Currents dice, 3 yellow Search dice, and 1 red Strike die (as indicated on the Shark's player aid).
Place the remaining dice within reach of the Shark to form the supply.
Shuffle the Shark deck, deal 4 cards face-up to the designated row, and place the rest of the deck face-down in the space to its left.
Place the 4 Growth tiles with the sides showing the spaces for the dice face-up, in the corresponding numbered slots.
From the Octopus cards, remove all starter cards with the special starter symbols and set them aside.
Separate the remaining Octopus cards by color and form 4 piles: Learn (blue), Eat (orange), Hide (purple), and Move (yellow).
Shuffle each pile individually and place it face-up on the Octopus player's side of the table.
Place the matching food block on the top Eat card.
Place the other 3 food blocks, 1 shell, 1 double shell, and the 3 traps next to the card piles.
Place the hand size token with the number 4 facing up on the space above the draw pile.
Place the 3 Shark and 3 Octopus confrontation cards face-down next to the board.
Put the remaining 9 blocks (1 Octopus, 1 trap, and 7 shells) into the Octopus bag.
The Octopus shuffles the blocks in the bag and draws them one at a time, placing them standing upright in the block spaces (from top to bottom, left to right).
Only the Octopus should see the block symbols. Once all blocks are placed, put the bag to the side.
Take the card Fast Learning and set it aside.
Shuffle the remaining starter cards and place them face-down to form the draw pile.
The Octopus takes the starting card Fast Learning and draws 3 additional cards from the starting deck to form the opening hand.
The Octopus places the Shark on 1 of the 4 dens, on a Current space, pointing at the center of the board.
The game begins. The Octopus takes the first turn.

The Octopus
As the Octopus, you play cards that let you move stealthily and manipulate the position of the blocks on the board. Most cards come at the cost of revealing blocks, but some cards let you hide them again.
Your goal is to survive - win by outlasting the Shark until it is exhausted, or by feasting on all 4 food blocks.
Playing the Octopus is a strategic role: manage your available actions and balance the need to move, hide, and even bluff to confuse the Shark.

• Blocks
  Adjacency. Blocks are adjacent when orthogonally next to each other, not diagonally.
  Revealed. Blocks are revealed when they lie horizontally with the icon facing up. Both players can see the icons.
  Hidden. Blocks are hidden when they stand vertically with the icon facing the Octopus. The Shark should not be able to see the icons on hidden blocks.

• Actions
  On your turn, you must take two actions. You may perform the same action twice. There are three possible actions:
  • Play a card. After choosing a card, first pay its cost by revealing the number of hidden blocks indicated on that card. The cost varies between 0 and 3 and must always be paid in full. Each block you reveal usually counts as 1. You can reveal any of your blocks, including food, traps, and the Octopus. After paying the cost, perform the effect on the card. You must be able to complete the full effect to use it; otherwise you can't play the card.
  • Draw back to the size of your hand. You may choose this action if you have fewer cards than your hand size. If your hand is empty, you must perform this action. Whenever you need to draw but your draw pile is empty, shuffle your discard pile to form a new draw pile. You always draw up to your hand size. At the start of the game your hand size is 4 cards. The Octopus does not automatically draw at the end of its turn - drawing is an action.
  • Discard 1 card from your hand, then hide 1 block if possible. Put the discarded card on the discard pile, ignoring its cost and effect, then you may hide one of your revealed blocks.

At the end of your turn, move any cards you played to the discard pile.

• Card Effects
  There are 4 types of cards:
  • Move. Move cards let you move the blocks around the board in two ways: by swapping or by shuffling.
    Swapping means exchanging two orthogonally adjacent blocks. They must be swapped in the same state they were in before: a hidden block remains hidden, a revealed block remains revealed.
    Shuffling means taking a certain number of hidden blocks from the board and placing them into the Octopus bag. Shake the bag and, without looking, pull out the first block (be careful not to reveal it to your opponent). The Shark must indicate an empty spot on the board where you place the pulled block. Repeat until all blocks are back on the board. Shuffling randomizes the blocks - they may end up in the same zone as before, but the Shark doesn't know this.
  • Hide. Hide cards let you stand your blocks back up to hide them again. Hide cards can be played at no cost.
    
  • Learn. Learn cards improve your skills - improving your deck by gaining better cards and new blocks. For example, Learn 2 lets you gain either 2 new cards, 2 new blocks, or 1 card and 1 block.
    When you gain a new card, place it on your discard pile unless otherwise stated on the card you played.
    When you gain a block, you must exchange it with a revealed block on the board. New blocks enter the game revealed. Exchanged blocks are set to the side of the board. You can only gain blocks if you have the required number of revealed blocks on the board.
    If you gain an Eat card, you also get the matching food block for free. An Eat card and its matching block count as 1 when playing Learn.
    Some card effects let you trash cards, removing them from the game to make your deck more efficient.
    
  • Eat. One way for the Octopus to win is to play all 4 Eat cards to eat all the food blocks. To eat a food block, it must first be in play on the board (gained via Learn). Then you must:
    • have the Octopus block orthogonally adjacent to the food block, and
    • have the matching Eat card in your hand.
      As an action, play the Eat card, then reveal the matching food block and the Octopus (if they aren't already). Now you have eaten. Replace the food block with a spare shell (revealed) and place the food block on the lowest available space on the Food Track. Trash the used Eat card. The Octopus remains revealed until you play another card to hide.
      Eaten food blocks reward you with a one-time additional free effect (see Blocks below). To activate a food block, turn it face-down to indicate its effect has been used. You can use it before, after, or in between your 2 actions. If you place a food block on the last spot on the Food Track, you win.

• Blocks Explanation
  • Food effects (activated by the Octopus)
    • Red Rock Crab. Flip the hand size token to 5. Your maximum hand size is now 5 for the rest of the game. In addition, you immediately draw up to your hand size.
    • Sea Snail. You can search your draw and/or discard pile for a specific card and add it to your hand, ignoring the maximum hand size for that turn. After searching the draw pile, you must shuffle it.
    • Cape Rock Lobster. You can immediately hide all your revealed blocks.
    • South African Abalone. You may learn up to 3 for free. Gained cards go to the discard pile; gained blocks must be exchanged with already revealed blocks on the board.
  • Trap effects (triggered by the Shark)
    Traps are blocks placed by the Octopus but only triggered by the Shark, by revealing them through searching or striking. When triggered, they usually have negative consequences for the Shark.
    • Hide 2 blocks. The Octopus can immediately hide up to 2 blocks. This trap block cannot be hidden with this effect.
    • Discard 1 Current. The Octopus can remove 1 Current from the board. It goes back into the Shark's dice bag.
    • Discard 2 Currents. The Octopus can remove up to 2 Currents from the board. They go back into the Shark's dice bag.
    • Move the Shark to a den. The Octopus moves the Shark to any free den space on the board, positioned like the Shark's starting position. If all dens are covered with Currents, remove one Current (back into the Shark's dice bag) and place the Shark there. Place the Shark at a 90-degree angle to the Shark's path, so the Shark can choose to go left or right.
  • Other blocks
    • Shell. Shells are found scattered throughout the Kelp forest. They have no specific function.
    • Double Shell. The double shell lets you play a card for a cheaper cost. Revealing the double shell is equivalent to revealing any other 2 blocks.
    • Octopus. This block represents you, the Octopus. It can never be removed from the game.

The Shark
As the Shark, you swim around the Kelp forest from one Current space to the next. You roll different dice to move, search, and strike. With each turn you can become stronger - improving your dice bag and learning new skills - as you chase the Octopus. However, as your skill level increases, so does your hunger for victory: pushing yourself too hard may exhaust you prematurely. The only way to win is by successfully striking the Octopus and beating it in the final confrontation. Playing the Shark is a tactical role: mitigate the luck of the dice and use memory and deduction to keep track of the blocks as they move.

• Shark Turn Order
  The Shark's turn has several steps. Only Draw and Roll and Move must be performed every turn, but keep the order in mind:

1. Draw and Roll (2 dice)
2. May place Currents
3. Move
4. Search / Strike
5. Growth
6. Energy
7. Place remaining dice(may get cards)

• Draw and Roll
  On your turn, first draw 2 dice from your bag and roll them once. The rolled dice form your pool, which you will place in later steps. Later in the game you may be able to draw more than 2 dice.
  There are 3 Types of dice:
  
  • Currents (blue). Let you place Currents so you can swim faster across the board.
    
  • Search (yellow). Let you search for the Octopus by revealing blocks.
    
  • Strike (red). Let you strike, meaning attacking a block where the Octopus might be.

• May place Currents
  Currents let you swim faster. You may place Currents on any empty Current space, regardless of proximity to the Shark. You may also keep Current dice in your pool to place them later as stored Energy.

• Move
  Following the lines, you must move each turn, usually to the next empty space. You can't move backwards, stand still, or turn 180 degrees before moving. You can't stop on a space with a placed Current.
  By moving over Currents you can swim further, skipping the spaces that have Current dice. You can use a single Current or create chains of Currents to swim even further. A chain of Currents consists of several blue dice placed on connected spaces. However, you can only use a chain of Currents from higher to lower numbers. The numbers don't have to be consecutive, but each die you swim over must be lower than the previous one.
  After swimming down Currents, regardless of length, remove the first die you swam over and place it on the next empty space on the Growth Track. If there are no empty spaces left on the last Growth tile, put the die back in the dice bag. (By using card effects and stored Energy, you may move more than one space a turn, or even swim the opposite direction.)

• Search / Strike
  If you have rolled yellow and/or red dice, you may choose to search and/or strike in 1 or 2 zones to which you are orthogonally adjacent.
  
  • Placement.
    The value of each die you place must be equal to or greater than the indicated zone value; otherwise you can't place it and it remains in your pool.
    Only one die can be placed on a single empty value space.
    If you have more than one search and/or strike die to place, you must first place both dice and then decide which block will be revealed first. The Octopus must then reveal it.
    You can also keep the dice in your pool and place them later as stored Energy.
    
  • Search.
    Searching reveals the block.
    To search, use a yellow die.
    You can only search zones with hidden blocks.
    Used yellow dice are placed on the next empty space on the Growth tiles; if there are no empty spaces left, return the dice to the dice bag.
    
  • Strike.
    Striking reveals the block (if it isn't already) and you attack it.
    To strike, use a red die.
    You can strike hidden blocks or, of course, the Octopus if it is already revealed.
    If you strike the Octopus, immediately proceed to a confrontation.
    After a possible confrontation or a strike against another block, used red dice are placed on the bottom empty space on the Hunger Track immediately after each strike. Dice placed on the Hunger Track remain there until the end of the game.
    
  • Additional effects for Search and Strike.
    If you trigger a trap, its effect comes into play.
    If you find shells or food, there is no effect.
    If you find the Octopus with a search die, you now know its position; apart from that, there is no effect.
    In any case, the blocks remain revealed.

• Growth
  The Growth Track grants you permanent abilities. Following the Move and Search step, place the 1st used Current and all used search dice on the next empty space on the Growth tiles, proceeding left to right.
  Once you have placed 3 dice on a tile, return them to the dice bag and flip the tile. The ability stated on the tile is now always active. After activating all 4 tiles, used Currents and search dice are put back in the bag at the end of the Move and Search steps. Red strike dice can never go on the Growth Track.
  The Growth abilities (in track order) are:
  • You may reroll one die each turn (before Move).
  • When you use stored Energy but have 5 or less, gain 5 additional Energy (during Energy).
  • You may reroll an additional time each turn (before Move).
  • You may draw 1 extra die each turn (during Draw and Roll).

• Energy
  In this step, you must place all remaining dice from your pool in the Energy slots as stored Energy. If you have 1 or 2 dice in stored Energy, you can get new cards. If you have 3 dice stored, you must spend stored Energy to get one or more new cards this round.
  The sum of the pips (regardless of color) on all your dice in the Energy slots can be used to obtain cards that give one-time special effects and additional dice for future rounds.
  You can get any number of the available cards whose total cost is equal to or less than the sum of the pips.
  Each time you get a card, immediately refill the empty spot with a new card from the deck.
  Any of the sum not spent is lost at the end of the step. Getting new cards is the only way to get new red dice, which you need to strike and win.
  Additionally, once per turn you may reduce a single die by 1 to discard any of the 4 available cards and replace it with the top card from the deck. A die may never be reduced below 1.
  When you get a new card, immediately add the dice shown on the card to your bag.
  When you spend stored Energy, you must select one of the stored Energy dice and move it to the next free space on the Hunger Track; the remaining dice (if any) go in the dice bag.
  If you place a die on the last available space of the Hunger Track by using stored Energy (or by striking), you are exhausted and the Octopus wins.
  Shark cards have one-time-use effects; when a card has been used, place it face-down and trash it. Cards show a cost, a name, a phase in which to use them, an effect, and the dice you get.

• Confrontation
  When the Shark strikes a block with a red die and it's the Octopus, you immediately start a confrontation.
  The Octopus has 3 survival strategy cards, in the colors yellow, red, and gray. The Shark has 3 cards of the same colors that each counter one survival strategy.
  The Octopus and the Shark each secretly choose one confrontation card and place it face-down. Then both reveal their chosen card simultaneously.
  If the Shark chose the counter card that matches the Octopus's card, the Shark successfully attacks and immediately wins the game.
  If the Shark did not choose the color-matching card, the Octopus escapes and can perform the survival strategy described on its card.
  After a successful escape, discard the used Octopus confrontation card and the matching Shark card from the game (both red "Fight" cards are trashed after a red confrontation, for example). On the next confrontation there is a 50-50 chance the Octopus escapes. On the third confrontation, the Shark definitely succeeds and wins the game.

• End of Game
  There are 3 ways the game can end. The Octopus has 2 ways to win, the Shark has 1.
  Octopus victory:
  By eating all the food. The game immediately ends when the Octopus places the 4th food block on the Food Track.
  By hiding long enough until the Shark is exhausted. The game immediately ends when the Shark places the 7th die on the Hunger Track.
  Shark victory:
  By successfully striking the Octopus with a red die and beating it in the confrontation.

FAQ
Discard and trash piles. The Octopus's discard pile and both players' trash piles are public knowledge; players may look through them at any time.
Spare shell. A spare shell block is included in case an eaten food block needs replacing but all other shells are already in play.

Shark FAQ
Dens. At the start of the game, and whenever you are returned to a den (by a confrontation card or a trap effect), you are considered to already be on the Current space in front of the den, pointing at the center. On your turn you choose which direction to head when leaving the den.
Dice bag. You may look into the dice bag at any time, but must always shake the bag before drawing. The Octopus may never look into your bag.
Draw and Roll. If you ever need to draw dice but your bag is empty, remove Current dice from the board until you have 2 dice to roll.
Move. If you can't make a legal movement (due to ascending Currents or otherwise), return the closest Current die to the bag and move into that space. If two dice are equally close, choose which one to return.
Growth. After activating the second tile, you can only use it if you have at least 1 die in the Energy slots.
Placing dice into stored Energy. If you place more dice into stored Energy than there are free spaces, choose which dice to place; any others are returned to the bag.
Energy step. If you have all stored Energy spots filled but can't afford any available cards and can't reduce the dice any lower, return all dice to the bag without moving a die to the Hunger Track.

Card Clarifications

• Shark cards
  Shark cards have one-time-use effects. When a previously acquired card has been used, place it face-down and trash it.
  • Aggressive. Has no effect other than giving you red dice.
  • Agile. Before moving, make a double-back (180-degree) turn.
  • Daring. Before moving, move any other die in your pool to the Hunger Track and immediately turn a red strike die that is also in your pool to a 6.
  • Hostile. Shuffle the remaining Octopus confrontation cards face-down. Reveal one randomly and trash it. Take the matching Shark confrontation card and trash it as well.
  • Hungry. During the Draw and Roll step, draw an additional die and roll it once. This can be triggered after drawing and rolling the standard number of dice for that turn.
  • Observant. Ignore the effect of a trap. This takes place during the Search/Strike step, after a trap has been revealed.
  • Reactive. During the Draw and Roll step, return 2 dice to the bag, then choose a replacement die by looking in the bag. This takes place after drawing but before rolling.
  • Relentless. Reroll 1 or 2 dice, before moving. This can be used together with the rerolls from the Growth tiles (to reroll a die twice, or to reroll more than 1 die).
  • Ruthless. Before moving, increase the value of a die in your pool by rotating it to the new number.
  • Swift. During the Move step, move the Shark an additional space. This extra movement can be used before or after moving into a Current.
  • Vigilant. After rolling, save a die to use it in addition to a later turn. Place the saved die onto the face-down Vigilant card. On a subsequent turn you may retrieve it and place it during that turn. You may not change the die value, and this die is not considered part of the pool.
• Octopus cards
  • Trash effects. You can't use the trash effect of a card to trash the card itself.
  • Taking Chances (Move). The Exposed Zone is the center zone with the 2+ zone value. The block in the Exposed Zone can be hidden or revealed before the shuffle.
  • Cloud of Ink (Move). It is possible to reveal the Octopus as part of the reveal cost.
  • Sudden Evasion (Move). It is possible to include the same block in both of these swaps.
  • Sharp Senses (Learn). It is possible to gain Eat cards with Sharp Senses, but they can't be added to your hand - Eat cards go on your discard pile.

I found this on https://www.rulespal.com/ and edited it slightly..

Have fun with this great 2-player game.!