• 1 x set of resource tokens

These are available in both wood, plastic and from various 3D prining outlets.

In the rules below, "card" refers to the original resource cards supplied with the game, and "token" refers to the new wooden/plastic pieces.

• The resource tokens (sheep, brick, ore, grain and wood) are used for buying and trading exactly like resource cards. Buys or trades may use any mix of cards and tokens.
• When a player places the robber on a resource terrain hex, he may draw a card (not a token) from another player as per the regular rules, or he may instead take from the bank a resource token that matches the terrain hex.
• If a player upgrades a city with a city wall, that city now has the ability to generate resource tokens. Later when an adjacent terrain hex produces resources, the owner of the city may optionally take one matching resource token instead of a resource card as part of his earnings. The second resource or commodity must be taken as a card. Note: The city wall no longer adds additional protection (+2 cards) for the handcount. Instead, it allows the player to collect exempt tokens.
• When the resource production is calculated, if the requested number of a given flavour of token exceeds the balance in the bank, then none are distributed and all players must take cards instead. Of course, if the players really want tokens and can come to an agreement, they may elect to reduce the total demand for tokens by taking some cards instead, thereby allowing the bank to satisfy the remaining demand.
• The "greater than 7 cards" penalty applies only to resource / commodity cards. Tokens are not included in the card count.
• When returning resources to the bank to satisfy the "greater than 7 cards" penalty, the player can optionally discard a token that matches a card rather than discarding the card itself. In other words, the debt can be paid off with a mix of cards and tokens, as long as the tokens match individual cards that could have been discarded.
• Regular 4 for 1, 3 for 1 or 2 for 1 trades with the bank yield only resource cards not tokens. However, tokens can be used in combination with cards as the items to be traded.

C&K Rule Variations

• The Aqueduct city improvement yields only resource cards not tokens.
• When playing the Commercial Harbour card, the player may offer resource cards or tokens.
• The Resource Monopoly card only impacts resource cards, not tokens
• The Mining and Irrigation cards earn resource cards, not tokens
• The Wedding card only impacts resource / commodity cards, not tokens.
• The Master Merchant card only impacts resource / commodity cards, not tokens.
• The Saboteur card (4th edition rules) card only impacts resource / commodity cards, not tokens.
• The Bishop card can only be used to draw resource / commodity cards, never tokens.

The Fishermen of Catan Rule Variation

• A player can trade fish for resource cards but not for tokens. A player spending fish to draw from another player may only draw from cards, not tokens. 

Copyright: Credit for these rules goes to John, a long term and dedicated Catan fan. His site with this information on is johnnycruiser.com.