Gravity Shackles

Juuryoku Kihan (Gravity Shackles)
Ninjutsu (Doton) [Earth]
Rank: 7 (B-Class);
Area: 30-ft. radius sphere that moves with the user;
Duration: Concentration (up to 1 round/level) plus 3 rounds;
Saving Throws: Str negates;
Chakra Resistance: Yes;
Chakra Cost: 8.

For the duration of the technique, every creature in the area of effect will be unable to run or charge, suffer a -2 penalty to attack and weapon damage rolls and all carried items and creatures will see their weight increased by 50% (including the user, but the user's increased weight has no impact other than on the environment, such as soft ground giving way under him, etc). Affected creatures also suffer a -20 speed penalty, which can be lowered by 10 for every 20 strength they have (minimum 0).

A successful Str save negates the effect even if the creature exits and re-enters the area of effect, until the technique is renewed and a new save is required.