The closest you can get to a Free Trial is the beta test. Sign up for the forums at www.vanguardsoh.com and you will receive an application to join the beta test at the start of a new phase.

When the game is released, Sigil may release a demo version allowing players to try out a limited version of the game for free. This is not very common with MMORPGs.

There will, of course, be a free trial period for subscription to the game, but this will only come with the purchase of the game. As with most MMORPGs Sigil will give out at least a month of free play when you buy the game.