Counter Strike Online Wiki
Bot Zombie Mod
Bzm bigtree cso
Big Tree

Big Tree (bzm_bigtree) is the first Bot Zombie Mod map in Counter-Strike Online.


Big Tree is the first map that supports the Zombie Bot game mode. It promotes to basic Zombie: The Original system with the addition of bots. Bot navigation has been tweaked a bit so that it is compatible with Zombie modes. These modifications to bots are:

  • New function: zombie safe area.
  • No attack delay to all bots.
  • If one teammate is infected in a camping area, other human bots will rush to another safe area. There are two safe areas for bots in this map.

Release dates[]


This map was released alongside M32 MGL on:

  • South Korea: 28 June 2012 with Z-VIRUS patch.
  • Taiwan/Hong Kong: 4 July  2012 with Z-VIRUS patch.
  • China/Japan:  4 July  2012 with Z-VIRUS patch.
  • Indonesia: 10 April 2013.


This map was released alongside SKULL-1 on:

  • Singapore/Malaysia: 27 March 2013.


This map was released alongside MG3 on:

This map was released alongside Open Beta Test on:

  • CSN:Z: 23 September 2014.
  • Vietnam: 26 March 2015.


Special mission[]

Appointer Task Reward
Felix Kill 30 zombie bots in one day period.

Random cash weapons for 3 days or Level 2 Experience coupon.

Honor mission[]

Title Description Task
A medal will be given to the player who has unlocked the Difficulty Level, Elite, in Bot Zombie mode.
[Bot Zombie Master]
Gentleman, you shouldn't belittle on them just because they are dead. Don't forget they are zombies. Unlock Difficulty Level, 'Elite', in Bot Zombie Mod.



  • In the tunnel there are rats and bats; the bats will fly out once any player enters it. Near the big tree, there are also a few rats which can't be interacted with.
  • The rats model is taken from a cut model in Half-Life, while the bats model are taken from Banshee's Pulling ability.
  • This map is used as a tutorial map for Zombie mode.