Ressurection & Raising the Dead
Being dead is a traumatic event, and it will cost the PC not only money and resources, it will cost physically. 1 Con point will be lost per resurrection or raise dead performed. ONLY a wish spell, used for the purpose of bringing back the dead PC will negate the loss of the Con. A PC can only be resurrected or raised as many times as they have Con points.
In addition, PCs that were dead and brought back, will have to have 1-3 months of rest and downtime to fully recover from the experience. The standard is 1 month bedrest/light activity, but spellcasters may need more time to recover from the mental trauma ( Which would hinder concentration and clear thought ). For the first 1 hour of being ressurected, raised, etc... The PC will be in a mild coma and imobile, once regaining conciousness and thus returning to life, the PC will have to get that 1-3 months of rest to fully recover. Until that rest period is taken, all ability, skill, and attack rolls, and saves will be at -4 and spellcasting/memorization of spells will not be possible. Movement is also halved.
It's old school, but scares the crap out of players.