Yes, there's an Offline Practice mode in the training tab which you can use to play with bots immediately. However, that method has very limited options when it comes to customizing your game, and your stats won't be tracked. You also won't be able to get achievements this way.

These artificial players are far from perfect; they won't work at all in certain game modes. It's usually said that the simpler the game mode, the more likely it is to be compatible with bots.

• Assault (Attack/Defend)
  
• Payload
  
• King of the Hill

• Control Points
  
• Capture the Flag

• Payload Race
  
• Arena
  
• Special Delivery
  
• Mann vs Machine
  
• Mannpower
  
• PASS Time
  
• Player Destruction

• Cactus Canyon
  
• Snowycoast

Certain maps such as Dustbowl come with a nav mesh needed for bot functionality already installed. However, for any map, here's a list of steps to make bots (more or less) compatible with any map that uses a game mode that's compatible.

Start a server and press "~" (the key to the left of 1) to open up the console (enable the console through the options menu). Type the following commands in the console.

sv_cheats 1
nav_generate

This will automatically generate a nav mesh for the map, for which bots can use to move around and fight. It's not perfect, but it does in a pinch.

Here are some console commands that will help customize your bot-filled server.

Adds a bot with the specified parameters.

"tf_bot_add 3 red sniper 1 ROBOT" will add 3 red Snipers at the normal difficulty level named "ROBOT". For Heavies, use the word "heavyweapons"

Whether or not bots will change their class after dying.

"tf_bot_keep_class_after_death 1" will always have the bots use the class they've selected at the start of the game. Perfect for making your dream team!

How often a bot will taunt upon killing a human victim.

"tf_bot_taunt_victim_chance 0" means that bots won't taunt victims.

The default difficulty of bots created. The higher the number, the more difficult the bot.

"tf_bot_difficulty 3" will make every bot spawned after this command at expert difficulty

Forces all bots to play as the specified class.

"tf_bot_force_class scout" will make all bots scouts

Whether or not bots can only use melee weapons.

"tf_bot_melee_only 1" will force all bots to use melee weapons. It's gonna be a rough fight!

Kicks all the bots from your server.

Determines whether or not autobalance is in play, and if players can join any team regardless of the teams' sizes.

"mp_autoteambalance 0; mp_teams_unbalance_limit 0" will remove that pesky autobalance from your server.

For those of us who like to play alone from time to time, inputting these commands over and over gets tiresome. Luckily one can make key binds to execute many of these commands at once. Here's a setup I like to use:

bind [key #1] "tf_bot_keep_class_after_death 1; tf_bot_taunt_victim_chance 0; mp_autoteambalance 0; mp_teams_unbalance_limit 0"

bind [key #2] "tf_bot_add 1 red heavyweapons; tf_bot_add 1 red medic; tf_bot_add 1 red soldier; tf_bot_add 1 red pyro; tf_bot_add 1 red sniper; tf_bot_add 1 red demoman; tf_bot_add 1 red spy; tf_bot_add 1 red engineer; tf_bot_add 1 red scout"

bind [key #3] "tf_bot_add 1 blue heavyweapons; tf_bot_add 1 blue medic; tf_bot_add 1 blue soldier; tf_bot_add 1 blue pyro; tf_bot_add 1 blue demoman; tf_bot_add 1 blue sniper; tf_bot_add 1 blue spy; tf_bot_add 1 blue engineer; tf_bot_add 1 blue scout"

From this point on, all you need to do when you start a game is to press those three keys in sequence. You'll have two teams of nine players, all different classes.

Note: You can achieve the same effects with a config file and bind them to a single key.

• During setup time bots will taunt when stared at long enough.
  
• Bots can also be interacted with via group taunts. It's possible to get taunt-specific achievements provided that you have the taunt yourself.
  
• Medics will use their Ubercharge when using the voice command "Go!" or "Activate Charge!".

This didn't happen at first; Engineers often simply detonated their structures once a team advances past a point (since they can't actually move their structures). This sadly no longer happens, and has made them broken for the longest time.

A handy solution is to kick all bots and spawn them all again. Sure, it resets all their points, but who's keeping score?

There's a piece in the nav mesh that the bot is mistaking for a way through, usually through a one-way passage. Try going into nav editing mode and deleting the offending element. That often works.

Feel free to leave constructive comments below, and don't hesitate to mention anything I've missed. Trolling/harassment comments will be removed.