Chad is consistently engulfed in political turmoil and attacks from rebels will probably not happen, but are certainly a reality. The situation has stagnated, but it remains a threat. Violence from the Darfur conflict is pouring into Eastern Chad from Sudan, a country which shares hostilities with Chad. Any activity outside of N'Djamena is done with difficulty at best. Northern Chad is barren, scorching desert and guides good luck and meticulous planning are required.
N'Djamena is RELATIVELY safe, although one should be wary of petty street crime and corrupt police/officials. Most border crossings are extremely difficult Sudan and Libya not being a viable option although the border crossings with Niger and Cameroon are relatively painless.
Don't accept water from any stores unless you know the brand. Eat only your own food that you buy in grocery stores. Avoid restaurants whenever possible. Stay away from people that look sick, there are many diseases in Chad to beware of. Go to a doctor once a month if you can afford it.
Citizens of the following countries do not require a visa: Benin, Burkina-Faso, Cameroon, Republic of Central Africa, Congo, Ivory Coast, Gabon, Equatorial Guinea, Mauritania, Niger and Senegal.
For all others, a visa is necessary. A single-entry visa costs US$100 for 1 month and multiple-entry visas cost US$150 3 months or US$200 6 months. A letter of invitation is required.
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There are 200 distinct ethnic groups. In the north and center: Arabs, Gorane Toubou, Daza, Kreda, Zaghawa, Kanembou, Ouaddai, Baguirmi, Hadjerai, Fulbe, Kotoko, Hausa, Boulala, and Maba, most of whom are Muslim; in the south: Sara Ngambaye, Mbaye, Goulaye, Moundang, Moussei, Massa, most of whom are Christian or animist; about 1,000 French citizens live in Chad.
The Chadian-Libyan conflict is something to be avoided at all times; Chadians known to be living in Libya have been tortured & murdered on previous occasions.
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The main languages of Chad are French and Arabic. Few Chadians other than the educated and well-traveled speak literary Arabic, however; a dialect of Arabic known as "Chadian Arabic" is much more widely spoken and is the closest thing the country has to a trade language. Chadian Arabic is significantly different from Literary Arabic, but similar to the dialects of Sudan and Egypt. Literary Arabic speakers can typically understand Chadian Arabic but the reverse is not true. There are over one hundred indigenous languages also spoken.