Always inquire about the rules before playing Roulette. The Surrender Rule works only for even money bets and reduces the House Edge to 2.63%. This rule applies when the ball lands on 0 or 00 you only lose half your bet rather than the full amount.
This is how the math runs:
E = [18/38 x (+1)] + [18/38 x (-1)] + [2/38 x (-0.5)]
E = -1/38 = - 0.0263
House Edge = 2.63%