Trebuchet Competition


The Playing Field

  1. The matches will take place in the arena of the WSU Nutter Center.
  2. Captains will have 5 minutes to position their target and trebuchets.
  3. Trebuchets may be positioned any place on your side of the playing field, outside of the Neutral zone.
  4. To start the match, all but one trebuchet will be positioned by the captain on or behind the "Long Line." The remaining trebuchet must be positioned between the Short Line and the Long Line.
  5. On each side of the playing field, outside of the neutral zone, but at the discretion of the team, there will be a single target representing the opposing team's main target. In order to win, a team must either knock out (hit) the opposing team's main target or eliminate all opposing trebuchets. The pole/base is not considered to be part of the target. The size of the main target may be changed between matches (in order to expedite matches), but will always be equal for both sides during any given match.
  6. The boundaries of the playing field will be marked.
  7. A target knocked off the post due to the impact of a projectile IS considered to have been hit.


  1. The match will start at the sound of a horn. Trebuchets fire at will once the match starts. Trebuchets that aren't ready are valid targets for the opposing team. Trebuchets that aren't set up with targets when the match begins may not enter the playing field during the match and must immediately vacate the field.
  2. Firing of the trebuchet will be performed by release of the projectile and/or its sling. No other moving part of the trebuchet may be touched during firing.
  3. Trebuchets are eliminated from a match when their targets are hit by enemy projectiles.
  4. Trebuchets are eliminated for the remainder of the match. They may be "rebuilt" to "fight another day."
  5. Friendly fire may eliminate a trebuchet by hitting its target.
  6. Trebuchets may not legally eliminate an enemy target using anything other than a squash ball thrown by a trebuchet.
  7. Projectiles are NOT considered harmless once they have struck the ground. That is, hitting the target off a bounce counts.

trebuchet battlefield graphic


  1. A clock judge will be responsible for timing advancement on the match field. At the clock judge's determination, trebuchets may advance one line (i.e. from the Long Line to the Short Line) or retreat.
  2. Only 10 seconds will be allowed for the move.
  3. Both teams may move during the 10 second period, and no firing can take place.
  4. There will be only two moves in the entire match.
  5. Trebuchets may not screen one another, or be positioned to screen their target.
  6. You may not advance your trebuchet outside of the playing field.
  7. Trebuches may be pivoted (rotated) for aiming.
  8. No match will be given more than 20 minutes, including setup time. If a match ends by decree, then the judges will vote for a winner.


  1. Operators must not interfere with in-flight projectiles. Operators who are considered to have potentially protected one of their targets by interfering, intentionally or not, with their bodies or other trebuchets will have that target removed. (Hint: don't stand in front of the target. You become the target to hit, if the judge thinks you are in the way.)
  2. No part of the trebuchet may interfere with an opponents projectile. If a projectile hits a part of a trebuchet that shades the target (the trebuchets target, or the main target), the trebuchet is considered to have been hit.
  3. You may not hoard squash balls. You must return squash balls that your team is not using. If your team at any time has 75% or more of all of the projectiles (there will be a total of 20 or more), the assistant must send (by rolling) no less than 10 projectiles to the opposing team. Targets hit while the opposing team is low on ammunition will be considered undamaged at the discretion of the judges.
  4. All judge decisions are final. Under no circumstances shall a video replay of an event be used to reverse a decision.