To make battle sync with everything we need a speed system which is not
limited to one round. Every round is divided to 10 segments, and in each
segment a amount of player's speed rating (usually 100) is added to
player's energy and when the player have at least 1000 energy points he is
able to act and after that the player's energy is reduced by 1000.
Therefore, if we have speed of 200 we are able to act twice per round.
However, if we have speed of 101 we are still able to act more than
once per round as the time passes. If we are slower, we will lose turns
periodically. As we use 10 segments, the maximum is to act 10 times per
round and never more. 

Fast characters will rule, they can use hit & run tactics and kill
monsters before they can react, and thus giving speed bonuses should be
very, very rare and expensive.