One student is IT, and if he/she tag someone, that person must freeze in place. A person who is frozen can be freed if someone other than IT tags them. If someone gets tag 3 times, then they become IT.
Boundaries need to be established for this version. Basketball courts seem to work very well. All of the players line up at the end of the field or court. When the IT yells GO!, everyone has to run for one end of the field/court to the other. On being taged, they link arms with the IT and form a chain, trying to catch the other students.
Choose an It. The rest of the players get into line of 3, with each person holding the waist of the person in front. IT tries to attach themselves to the last person in any line of 3. If he/she succeeds, the forn person of that line beacomes IT. If anyone in a line lets of the person in front, that person becomes IT.