Syndicates are where players can join together to fight against other groups of players. To first start a syndicate, you must have a syndicate level of 2. Leveling up your syndicate costs money and the max level is 10. Leveling will costs tokens after Syndicate Level 7.
The level of your syndicate determines which ladders you have access to. Level 2 Syndicate players will have access to only ladder 2, Level 3 Syndicate players have acess to ladders 2 and 3, and so on. Each can hold a certain number of critters, starting with 2 in Ladder 2 and adding one spot for each Ladder thereafter.
You can place a critter into a ladder by clicking the edit button and then selecting a critter. Each critter may only be in one ladder at a time.
To challenge, simply choose a team you would like to attack, and click Fight.