After playing TOR for several years now, one thing I learned was that you never know everything about the game.
This list contains all little secrets we've found, not everybody knows about:

• Body Type: Your body type is more than just aesthetic. Body type 4 (the fat one) makes you jump much slower and can give you a hard time at some Datacrons. There is one on Alderaan you can't get at all. The same goes for female body type 4 even though it's not as fat as the male one.
  
• Bantha Drifts Tunnel: to reach the imperial area of Tatooine (southern Jundland Wastes) most guides tell you to run through the imperial defenses. An easier method is taking the secret tunnel, just north of the imperial outpost Zaroshe hidden as a crack in the wall of a Tusken camp.
  
• Putting a mainhand or offhand hilt or barrel (specifically stated in item description) into a weapon for both hands causes the weapon to be bound to that specific hand. This is irriversible!
  
• A lot of bonus objectives can be done outside of the radius shown on the map.
  
• The F2P limit for only 3 boss loot in flashpoints only counts for normal mode FPs and not HM or tacticial FPs. In addition the counter is a bit buggy and might not count looting the boss from time to time.
  
• Kills in a flashpoint or warzone count towards the achievements 100/1000 enemys defeated with a certain companion and Organic Meatbags destroyed/decimated (HK PvP kills) for the active companion even when he/she/it are not present. This companion will appear as "locked" in your companion window and crew skill tab.
  Important for the new “Devotion to the [Class]” Achievement which grants the Imperial/Republic Squad Commander title!
  
• Gathering lockboxes through slicing with other group members in the vicinity causes this box to be tradeable for some time (similar to orange flashpoint loot).
  
• When you send a companion to a gathering node you can gather another node or go into stealth as soon as he/she starts the channel. Clicking the second node too early causes the companion to change direction and ignore the first one.
  
• After sending a companion away to sell junk items do not use a priority transport, fleet pass, or travel to your stronghold. Doing so will cause the companion to return without the money.
  
• Mob Spawn Rate: Bioware has had a lot of problems with bots. So spawn rates can depend on your behaviour when farming and the number of persons in your vicinity. (Based on experience in the Black Hole/Hypermatter Engeneering facility)
  
• In the Kuat Drive Yards Hangar Bay Scenario a stealther only needs to kill the groups in the back for completing "Defend the East/West Hangar".
  
• In the republic Mission The World Razor (Belsavis Intro Series) you can talk to Lord Chalos for social points/influence during the step "Use the Rakata Console".
  
• Some heroic missions can not be done alone despite the changes in 4.0:
  
  • [HEROIC 2+] For the Record and [HEROIC 2+] False History (Makeb)
    
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