Oh are you speaking of UHC mode? Where you only gain health from potions or gold apples? If so there is a command you can type in, dont need any mods at all, just a couple commands in the console or while oped on the server.
Here is what you need to type in:
Run these comamnds as OP as you setup the server
The only need to be ran once and are not player specific
*/
//add "playing" team
/scoreboard teams add Playing
//add death counter
/scoreboard objectives add Deaths deathCount Deaths
//Turn off health regen
/gamerule naturalRegeneration false
//Turn of day/night cycle
/gamerule doDaylightCycle false
//Set time of day to noon
/time set 8000
//Tracks players health in the tab menu
/scoreboard objectives add trackHealth health
/scoreboard objectives setdisplay list trackHealth
/* Build a clock that tests for these constantly */
/tp @p[m=0,r=50,team=!Playing] 0 [height of Obelisk] 0
/scoreboard teams leave Playing @a[score_Deaths_min=1]
/*
Put these commands in commands blocks for the Oblesisk to activate
There are 8 commands so these go in each of the comamnds blocks in the command ring
*/
//Clear death count
/scoreboard players set @a Deaths 0
//Add all playres to be playing
/scoreboard teams join Playing @a
//Set into desired difficulty,
http://www.minecraftwiki.net/wiki/Difficulty
/difficulty [1,2,3]
//Set gamemode to survival
/gamemode 0 @a
//Set spawn to center of map
/spawnpoint @a 0 [height of obelisk] 0
//Clear players inventory
/clear @a
//Give compass. This lets players always navigate to the center of the map
/give @a 345
//Heal Players to full
/effect @a 6 1 4
//Spread players: x z min_spread range respect_teams players. (- 50) to account for wall shadow)
/spreadplayers 0 0 400 [radius - 50] false @a
//Starting message
/say §2 "The games have become! Remember, you are either the hunter, or the hunted. Best of luck!"
/*
Here are some text tips for an additional command ring to fire after the first one has
*/
/say "Here are some tips:"
/say "1) Press tab at anytime to see everyone's health (/20)"
/say "2) If you feel ready to PvP, head to the center!"
/say "3) Hold right click with your sword to block incoming damage"
