Welcome one and all to the eleventh Twenty-four Hour Animation Contest! (Or THAC for short.)

THAC is a brickfilming contest that lasts for exactly 24 hours. All the idea-making, writing, recording, animating, editing and submitting is to be done within the time limit. It's a challenge, it's frantic, but it's a lot of fun!

The contest will begin on Saturday, December 28th 2013 at 12pm (midday) GMT and will run for 24 hours. It will end on Sunday, December 29th at 12pm GMT. You can see what that is in your time zone by clicking here.

Anyone is allowed to enter! You can work with someone else to make a co-production if you like. Just stick to the rules...

• Your entry must be made and submitted during the 24 hour period. I'll get onto how we moderate this later...

• Your entry must consist primarily of LEGO (or similar building-block toy) stop-motion animation. CGI, live-action or other forms of video may be used to supplement it, but the brickfilming must be the focus.

• Your entry must consist of at least 30 seconds of stop-motion animation.

• No mature/explicit content is allowed. This includes, but is not limited to: swearing, excessive violence, overt sexual content. The site is family-friendly and we ask that the contest entries are too.

NO! And we've got ways to make sure you don't!

• The contest theme will only be announced when the contest begins. Sure, you can brainstorm ideas beforehand but you could be way off what you're meant to make.

On top of that, we will enforce the use of two "mod elements".

• The first is a colour mod. This will be a combination of two random brick colours connected together. (e.g. a white brick connected to a grey brick)

• The other is a letter mod. This could be any letter of the alphabet, and you are allowed to use it in upper or lower case, and rotated or flipped in any way you can think of. As long as it's still recognisably that letter! (e.g. the letter L)

At least one of the mod elements must appear in every frame of your animation. Minifig parts (e.g. a white torso connected to grey legs) count towards the colour mod, but bricks connected to baseplates do not.

Details such as where and how to submit your film will be announced along with the theme and mod elements at the start of the contest, so don't worry about that yet.

This year's prizes have been supplied by our very kind sponsor, Brickworld!

Brickworld is a family of excellent LEGO fan expos, showcasing incredible LEGO builds year after year. The next scheduled ones are taking place in Indianapolis and Chicago, so if you're in the area you should definitely stop by.

You can find all the info on their site, Brickworld.us.

Prize Pool
This year we will have a prize pool rather than just straight-up prizegiving. This means that 1st place gets to choose which of the three prizes they want, 2nd place chooses from the remaining two and 3rd place gets whichever one is left over!

Ninjago Thunder Raider 70723

Superman vs. Power Armour Lex 6862

Cavalry Builder Set 79106

Don't be disheartened if you don't win - to have completed a THAC is an impressive feat in itself!
Special thanks to CarrollFilms for organising the prizes.

Some entrants like to document their THAC experience in video blog form, then edit it together after the contest ends to show people how much work went into cramming the entire filmmaking process into such a short amount of time.

Here's some examples of THACumentaries from previous contests: (1 2 3)

Spread the word! The fun of THAC is in knowing that there are loads of other people taking on the same challenge as you at once, so the more people the better. See you there!