How can I make a tag like gamemode in unity?

I wanna make a tag game but I dont know how to make other players it (and have the abilities and color) On collision? I already have movement, and ect. Also how do I make it so when everyones it switches to a random map?

Make your player script have an “private bool isIt = false”. Change it to true OnCollisionEnter.

Add a public property for the private isIt variable. This allows you to execute arbitrary code when getting or setting the value of said isIt variable. Use that to change the color. Also add / enable the “it” abilities through that property as well. Depends on how you implemented your abilities in the first place.

Using the same property, increment a global (public static) variable. Check if that variable is now equal to the player count. If it is, all players are “it”. In that case generate a random number between 0 and the number of maps you have. Make each map its own scene. Then simply load a scene based on the generated number.

There are a gazillion ways to implement any of this.
The above is just one possible rather quick to implement solution each.