Cheat Mode
Open Steam, go to your "Play Games" menu, and select Half-Life 2: Episode One. Right click on it and select "Properties". Click the "Launch Options" button then type -console. Click "Ok", then close. Double click "Half-Life 2: Episode One" to start the game. Once it is loaded and you are playing, press ~ to display the console window. Then, enter sv_cheats 1 and press [Enter] to enable cheat mode. You can now enter the following codes at the console window. Also, any code can be used as a command line parameter by prefixing it with the "-" character. Note: For games that were downloaded from Steam, to use cheats in single player mode, start the game with the -applaunch -dev -tconsole command line parameter.
god - God mode (server only)
give <item name> - Spawn indicated item
buddha - Reduce your health
hurtme <amount> - Damage player
impulse 101 - All weapons
notarget - Ignored by NPCs
noclip - Walk through objects (server only)
maps - List maps
map <map name> - Load indicated map
sk_max_357 <number> - Set max ammo for .357 Magnum
sk_max_ar2 <number> - Set max ammo for Pulse Rifle
sk_max_ar2_altfire <number> - Set max ammo for Pulse Rifle energy orbs
sk_max_buckshot <number> - Set max ammo for shotgun
sk_max_crossbow <number> - Set max ammo for crossbow
sk_max_grenade <number> - Set max ammo for hand grenades
sk_max_pistol <number> - Set max ammo for pistol
sk_max_rpg_round <number> - Set max ammo for RPG
sk_max_smg1 <number> - Set max ammo for submachine gun
sk_max_smg1_grenade <number> - Set max ammo for SMG grenades
sk_plr_dmg_pistol <number> - Set damage value for pistol
sk_plr_dmg_357 <number> - Set damage value for .357 Magnum
sk_plr_dmg_ar2 <number> - Set damage value for Pulse Rifle
sk_plr_dmg_buckshot <number> - Set damage value for shotgun
sk_plr_dmg_crossbow <number> - Set damage value for crossbow
sk_plr_dmg_crowbar <number> - Set damage value for crowbar
sk_plr_dmg_grenade <number> - Set damage value for grenades
sk_plr_dmg_rpg_round <number> - Set damage value for RPG rockets
sk_plr_dmg_smg1 <number> - Set damage value for submachine gun
sk_plr_dmg_smg1_grenade <number> - Set damage value for SMG grenades
npc_create npc_<name> - Spawns an NPC (see the list below)
NPC List
barnacle - barnacle
turret_ceiling - Ceiling Turret
citizen - City 17 Citizen
cscanner - Combine Scanner
combine_s - Combine Soldier
crow - Crow
fastzombie - Fast Zombie
ministrider - Hunter pigeon - Pigeon
seagull - Seagull stalker - Stalker
strider - Strider
vortigaunt - Vortigaunt
zombie_torso - Zombie without legs
zombie - Zombie
zombine - Zombine (Combine Zombie)
alyx - Alyx
antlionguard - Antlion Guard
antlion - Antlion
barney - Barney
breen - Breen
dog - Dog